According to RAW for Ancestral legacy, it says, if you choose Ancestral Legacy instead of 2 skills, you get: from the past race:  "any skill proficiencies you gained from it and any climbing, flying, or swimming speed you gained from it."

The Owlin gets stealth but for the other two, I don't see any innate skills. So does that mean if you choose past race as Aarakocra or winged Variant Tiefling you get the flying but no additional skill at all? You lose that reward for your character? It would seem that then, if you want to inherit a flying skill, Owlin is the only past race that makes sense. 

Am I misunderstanding anything?

Technically size and languages are determined by original race too and that information is just not in one place.

But other than that, yeah. If you want the highest flying speed or the option to fly in medium armor, just any flying speed and a skill, the owlin is the obvious choice.

I made a variant lineage with options of notable previous races that automatically gave the traits that carry over.

Quote from DxJxC >>

Technically size and languages are determined by original race too and that information is just not in one place.

But other than that, yeah. If you want the highest flying speed or the option to fly in medium armor, just any flying speed and a skill, the owlin is the obvious choice.

I made a variant lineage with options of notable previous races that automatically gave the traits that carry over.

I didn't see where it said you also inherit languages from the Ancestral legacy. It doesn't even say size! So theoretically you could be a fairy but grow larger after you become undead-ish? Do you see those specifics in the Ancestral Legacy descriptions? Maybe I missed it. Do you think my understanding is correct that since variant winged Tiefling and Aarakocra don't list any inherent skills, that if you choose them as your previous racial incarnation then you lose the skill? The trade-off really doesn't make much sense this way. You get 2 skills or 1 skill plus flying/swimming/climbing ability...unless that race didn't have an innate skill option in which case you only get the movement option. It really limits the smart choice. Like I said, why choose winged Tiefling when they don't have a skill vs. Owlin, you get stealth plus flying. Am I off base here?

I was just looking at one of my test DDB char sheets for this race and it says:

Quote from AGreaterMonster >>

 

I didn't see where it said you also inherit languages from the Ancestral legacy. It doesn't even say size! So theoretically you could be a fairy but grow larger after you become undead-ish? Do you see those specifics in the Ancestral Legacy descriptions? Maybe I missed it. Do you think my understanding is correct that since variant winged Tiefling and Aarakocra don't list any inherent skills, that if you choose them as your previous racial incarnation then you lose the skill? The trade-off really doesn't make much sense this way. You get 2 skills or 1 skill plus flying/swimming/climbing ability...unless that race didn't have an innate skill option in which case you only get the movement option. It really limits the smart choice. Like I said, why choose winged Tiefling when they don't have a skill vs. Owlin, you get stealth plus flying. Am I off base here?

You're not off-base in realizing that some races result in better Ancestral Legacies than others - for example, Lizardfolk make relatively superior ones.  In any case, you don't see the wording about size or language because the language rule is distinct from the Ancestral Legacy rule embedded in each of the 3 Lineage races and there isn't any size rule - any of the 3 can be Small or Medium regardless of the size of the "starter" race.  Here's the language rule you're missing:

If you are replacing your race with a lineage, you retain any languages you had and gain no new languages.

That's in the languages discussion prior to the individual discussions, and then the individual discussions all copy and paste the same Ancestral Legacy rule instead of having it in one place up top like the language rule is.  This is also known as "incompetent editing".

Another thing you may be missing is that Van Richten's has no rules at all for being certain of what constitutes a speed (or language), and relying on other rulebooks to answer the question (like the DMG and MM) results in... weird consequences.  For example, races that are fluent in specific animals (like gnomes and tritons) lose this because it's not technically language.  It can also get pretty confusing looking at what happens to certain Fly races, because we have no RAW whatsoever clarifying if armor restrictions on Fly speeds are inherited by Lineages.

I've posted this list before, but as some new races have come out since, like Owlin, may as well do it again.  Remembering that the baseline for all 3 Lineages is any 2 skills, any 2 languages, and no exotic speeds, with the major caveats that Reborn are breathless (so giving them a swim speed has extra benefit) and Dhampirs have a climb speed but better of 35 feet hands-free (so giving them a climb speed of that or worse has no benefit and anything above that has reduced benefit) - and since Dhampir have Walk 35 they also fly faster if they get Fly Walking - we get, as best in show:

• Swim Races
  • Elf, Sea, MTF: Languages 3, Swim 30, Skills 1
  • Lizardfolk, MMM: Languages 2, Swim Walking, Skills 2
    • Lizardfolk, Volo's:  Languages 2, Swim 30, Skills 2
    • Locathah, Locathah Rising: Languages 2, Swim 30, Skills 2
  •  All other playable races with a swim speed are strict subsets of the above 3 options (for example, Elf, Sea from MMM is a strict subset of Lizardfolk from MMM).
• Climb Races
  • Tabaxi, MMM: Languages 2, Climb Walking, Skills 2
    • Tabaxi, Volo's: Languages 2, Climb 20, Skills 2
    • Grung are worse than MMM Tabaxi but a side-grade from Volo's Tabaxi: Languages 1, Climb 25, Skills 1
  • Special mention: Van Richten's has no actual rule against double lineage, so if you have a permissive DM, you can make a Hexblood or a Reborn out of a Dhampir and retain the Dhampir's Climb Walking, which will cause a benefits cascade if you made your Dhampir out of a superior starting race.  But I assume no real-world DM will allow this.
• Fly Races
  • Aarakocra, EE: Languages 3, Fly 50, Skills 0 (no RAW on armor restriction)
    • Aarakocra, MMM: Languages 2, Fly Walking, Skills 0 (no RAW on armor restriction)
    • Fairy (WBTWW or MMM) is an exact match for Aarakocra, MMM
  • Owlin, SCC: Languages 2, Fly Walking, Skills 1 (no RAW on armor restriction)
  • Winged Tiefling, SCAG:  Languages 2, Fly 30, Skills 0 (no RAW on armor restriction, but armor restriction is lighter: Winged Tieflings can fly in Medium armor.  If restrictions are retained, this puts Winged Tieflings on the list of races worth discussing.)
• Speedless Races of Note
  • Half-elf, PHB: Languages 3, Speeds -, Skills 2
    • This is a challenging search; I found other races that tie this, such as Changeling (ERFTLW only - MMM nerfs their languages), but none that do better, and since the PHB is the one PC race source you can always count on having, I didn't bother with an exhaustive list.

So yeah.  The very short list for best Lineages is:

• Elf, Sea, MTF
• Lizardfolk, MMM
• Tabaxi, MMM
• Aarakocra, EE
• Owlin, SCC
• Winged Tieflings, SCAG, if Lineages retain armor restrictions on fly speeds
• Half-Elf, PHB

Ignoring Languages, since Xanathar's lets anyone learn infinite languages with downtime, eliminates Sea Elves and Half-Elves as being interesting, leaving us with MMM Lizardfolk, MMM Tabaxi, and the 2-3 Flying races listed above.

Quote from AGreaterMonster >>

Quote from DxJxC >>

Technically size and languages are determined by original race too and that information is just not in one place.

But other than that, yeah. If you want the highest flying speed or the option to fly in medium armor, just any flying speed and a skill, the owlin is the obvious choice.

I made a variant lineage with options of notable previous races that automatically gave the traits that carry over.

 

I didn't see where it said you also inherit languages from the Ancestral legacy. It doesn't even say size! So theoretically you could be a fairy but grow larger after you become undead-ish? Do you see those specifics in the Ancestral Legacy descriptions? Maybe I missed it. Do you think my understanding is correct that since variant winged Tiefling and Aarakocra don't list any inherent skills, that if you choose them as your previous racial incarnation then you lose the skill? The trade-off really doesn't make much sense this way. You get 2 skills or 1 skill plus flying/swimming/climbing ability...unless that race didn't have an innate skill option in which case you only get the movement option. It really limits the smart choice. Like I said, why choose winged Tiefling when they don't have a skill vs. Owlin, you get stealth plus flying. Am I off base here?

 Ok, I was wrong about size, but languages says "If you are replacing your race with a lineage, you retain any languages you had and gain no new languages."

Again the tiefling, Aaracokra, and owlin have different speeds and restrictions to their flying. The owlin has the weakest flying of the 3, but also gets an extra skill.

Why choose tiefling? Maybe to have a higher AC while flying. Why Aaracokra? Maybe to have 20 additional flying speed and a 3rd language.

Skills are useful, but you may be putting too much value on them. Characters are already guaranteed at least 4 skills. 1 or 2 more from race are extra, not expected.

Quote from quindraco >>

Quote from AGreaterMonster >>

 

I didn't see where it said you also inherit languages from the Ancestral legacy. It doesn't even say size! So theoretically you could be a fairy but grow larger after you become undead-ish? Do you see those specifics in the Ancestral Legacy descriptions? Maybe I missed it. Do you think my understanding is correct that since variant winged Tiefling and Aarakocra don't list any inherent skills, that if you choose them as your previous racial incarnation then you lose the skill? The trade-off really doesn't make much sense this way. You get 2 skills or 1 skill plus flying/swimming/climbing ability...unless that race didn't have an innate skill option in which case you only get the movement option. It really limits the smart choice. Like I said, why choose winged Tiefling when they don't have a skill vs. Owlin, you get stealth plus flying. Am I off base here?

You're not off-base in realizing that some races result in better Ancestral Legacies than others - for example, Lizardfolk make relatively superior ones.  In any case, you don't see the wording about size or language because the language rule is distinct from the Ancestral Legacy rule embedded in each of the 3 Lineage races and there isn't any size rule - any of the 3 can be Small or Medium regardless of the size of the "starter" race.  Here's the language rule you're missing:

If you are replacing your race with a lineage, you retain any languages you had and gain no new languages.

That's in the languages discussion prior to the individual discussions, and then the individual discussions all copy and paste the same Ancestral Legacy rule instead of having it in one place up top like the language rule is.  This is also known as "incompetent editing".

Another thing you may be missing is that Van Richten's has no rules at all for being certain of what constitutes a speed (or language), and relying on other rulebooks to answer the question (like the DMG and MM) results in... weird consequences.  For example, races that are fluent in specific animals (like gnomes and tritons) lose this because it's not technically language.  It can also get pretty confusing looking at what happens to certain Fly races, because we have no RAW whatsoever clarifying if armor restrictions on Fly speeds are inherited by Lineages.

I've posted this list before, but as some new races have come out since, like Owlin, may as well do it again.  Remembering that the baseline for all 3 Lineages is any 2 skills, any 2 languages, and no exotic speeds, with the major caveats that Reborn are breathless (so giving them a swim speed has extra benefit) and Dhampirs have a climb speed but better of 35 feet hands-free (so giving them a climb speed of that or worse has no benefit and anything above that has reduced benefit) - and since Dhampir have Walk 35 they also fly faster if they get Fly Walking - we get, as best in show:

• Swim Races
  • Elf, Sea, MTF: Languages 3, Swim 30, Skills 1
  • Lizardfolk, MMM: Languages 2, Swim Walking, Skills 2
    • Lizardfolk, Volo's:  Languages 2, Swim 30, Skills 2
    • Locathah, Locathah Rising: Languages 2, Swim 30, Skills 2
  •  All other playable races with a swim speed are strict subsets of the above 3 options (for example, Elf, Sea from MMM is a strict subset of Lizardfolk from MMM).
• Climb Races
  • Tabaxi, MMM: Languages 2, Climb Walking, Skills 2
    • Tabaxi, Volo's: Languages 2, Climb 20, Skills 2
    • Grung are worse than MMM Tabaxi but a side-grade from Volo's Tabaxi: Languages 1, Climb 25, Skills 1
  • Special mention: Van Richten's has no actual rule against double lineage, so if you have a permissive DM, you can make a Hexblood or a Reborn out of a Dhampir and retain the Dhampir's Climb Walking, which will cause a benefits cascade if you made your Dhampir out of a superior starting race.  But I assume no real-world DM will allow this.
• Fly Races
  • Aarakocra, EE: Languages 3, Fly 50, Skills 0 (no RAW on armor restriction)
    • Aarakocra, MMM: Languages 2, Fly Walking, Skills 0 (no RAW on armor restriction)
    • Fairy (WBTWW or MMM) is an exact match for Aarakocra, MMM
  • Owlin, SCC: Languages 2, Fly Walking, Skills 1 (no RAW on armor restriction)
  • Winged Tiefling, SCAG:  Languages 2, Fly 30, Skills 0 (no RAW on armor restriction, but armor restriction is lighter: Winged Tieflings can fly in Medium armor.  If restrictions are retained, this puts Winged Tieflings on the list of races worth discussing.)
• Speedless Races of Note
  • Half-elf, PHB: Languages 3, Speeds -, Skills 2
    • This is a challenging search; I found other races that tie this, such as Changeling (ERFTLW only - MMM nerfs their languages), but none that do better, and since the PHB is the one PC race source you can always count on having, I didn't bother with an exhaustive list.

So yeah.  The very short list for best Lineages is:

• Elf, Sea, MTF
• Lizardfolk, MMM
• Tabaxi, MMM
• Aarakocra, EE
• Owlin, SCC
• Winged Tieflings, SCAG, if Lineages retain armor restrictions on fly speeds
• Half-Elf, PHB

Ignoring Languages, since Xanathar's lets anyone learn infinite languages with downtime, eliminates Sea Elves and Half-Elves as being interesting, leaving us with MMM Lizardfolk, MMM Tabaxi, and the 2-3 Flying races listed above.

This is very helpful. Thank you! I have this vision for a Dhampir or Reborn character...I can see the personality for the most part, but I'm torn between Barbarian, Monk or Swashbuckler Rogue. It will depend on what the rest of my team wants to play, too. So many options, I'm paralyzed by choices. 

Quote from DxJxC >>

Quote from AGreaterMonster >>

Quote from DxJxC >>

Technically size and languages are determined by original race too and that information is just not in one place.

But other than that, yeah. If you want the highest flying speed or the option to fly in medium armor, just any flying speed and a skill, the owlin is the obvious choice.

I made a variant lineage with options of notable previous races that automatically gave the traits that carry over.

 

I didn't see where it said you also inherit languages from the Ancestral legacy. It doesn't even say size! So theoretically you could be a fairy but grow larger after you become undead-ish? Do you see those specifics in the Ancestral Legacy descriptions? Maybe I missed it. Do you think my understanding is correct that since variant winged Tiefling and Aarakocra don't list any inherent skills, that if you choose them as your previous racial incarnation then you lose the skill? The trade-off really doesn't make much sense this way. You get 2 skills or 1 skill plus flying/swimming/climbing ability...unless that race didn't have an innate skill option in which case you only get the movement option. It really limits the smart choice. Like I said, why choose winged Tiefling when they don't have a skill vs. Owlin, you get stealth plus flying. Am I off base here?

 Ok, I was wrong about size, but languages says "If you are replacing your race with a lineage, you retain any languages you had and gain no new languages."

Again the tiefling, Aaracokra, and owlin have different speeds and restrictions to their flying. The owlin has the weakest flying of the 3, but also gets an extra skill.

Why choose tiefling? Maybe to have a higher AC while flying. Why Aaracokra? Maybe to have 20 additional flying speed and a 3rd language.

Skills are useful, but you may be putting too much value on them. Characters are already guaranteed at least 4 skills. 1 or 2 more from race are extra, not expected.

Thanks for the pointers. 

Quote from AGreaterMonster >>

This is very helpful. Thank you! I have this vision for a Dhampir or Reborn character...I can see the personality for the most part, but I'm torn between Barbarian, Monk or Swashbuckler Rogue. It will depend on what the rest of my team wants to play, too. So many options, I'm paralyzed by choices.

This is the wrong forum for build advice, but I can point out that Monks get a special non-synergistic pseudoclimb and pseudoswim speed that means Dhampir and Reborn have reduced synergy with Monk.  The Dhampir bite can't be swung with Strength or Dexterity and isn't Finesse, so its primary utility is out of combat (snacking on ants from your portable anthill for healing or ability check buffing), and because 1d4+CON is usually better than 1d6, Dhampirs are better than Reborn at passing a skillcheck they see coming, while Reborn are better at passing a skillcheck that surprises them and/or passing skillchecks efficiently (as they can intelligently conserve resources when they do very well on a skillcheck).  The Dhampir super-climb is primarily of benefit when you need to do something while climbing with both hands, as most DMs will let you cling to a surface with both feet and one hand to free up the other hand. 

Also, make sure you check with your DM before you take any of the 4 flying options (just like if you didn't use a Lineage, you'd check before taking Protector Aasimar): some DMs restrict Flying races because they invalidate so much pre-written content in adventure modules.

Quote from quindraco >>

So yeah.  The very short list for best Lineages is:

• Elf, Sea, MTF
• Lizardfolk, MMM
• Tabaxi, MMM
• Aarakocra, EE
• Owlin, SCC
• Winged Tieflings, SCAG, if Lineages retain armor restrictions on fly speeds
• Half-Elf, PHB

 These are the options I made for my variant lineages homebrew (that I mentioned in my first comment). Lol.