feedback? also, these guys work together often.

I'm gonna make a cavailry

oh oops

if you use it in a campaign change it to CR2

I hope you make a lot more stuff like this though 

I will. also, I'm supposed to be "connorc" but I had a typo.

why does everyone ignore my stuff

Don't sweat it, I've published a fair bunch of stuff on DnDbeyond, and it's pretty rare for anyone to view or add my stuff, and I don't think I've gotten a single comment on one of them, even though I leave my own comment encouraging people to give feedback. I think it's because browsing through homebrew is a big cluttery mess, it's hard to find something unless you're specifically looking for it. Then people rarely add what they're looking at even if it's decent, they usually only add things that WOW them. People will look at something decent but normal like this and be like "well, I could make something like that" but then they don't bother to because they're lazy.

Here's some cleanup you can copy/paste. Also, they added a thing where monsters can have built in dice rolling (in the encounter builder I think?) and I've added that feature in, but if I type it correctly it vanishes in the comment, so I've removed the "e" at the end of each first "rollable" so after you copy paste you'll have to add the "e" onto the end of each "rollabl". And of course, you'll have to click "create new version" then republish the new version since this is already published.
I noticed while it had a shortsword it didn't have any way to use both swords at once if that was your intention so I've added that at the top.
Multiattack. The hobgoblin makes one longsword attack and one shortsword attack.

Longsword. Melee Weapon Attack: [rollabl]+4;{"diceNotation":"1d20+4","rollType":"to hit","rollAction":"Longsword"}[/rollable] to hit, reach 5 ft., one target. Hit: 6 [rollabl](1d8+2);{"diceNotation":"1d8+2","rollType":"damage","rollAction":"Longsword","rollDamageType":"slashing"}[/rollable] slashing damage, or 7 [rollabl](1d10+2);{"diceNotation":"1d10+2","rollType":"damage","rollAction":"Longsword","rollDamageType":"slashing"}[/rollable] slashing damage if used with two hands.

Shortsword. Melee Weapon Attack: [rollabl]+4;{"diceNotation":"1d20+4","rollType":"to hit","rollAction":"Shortsword"}[/rollable] to hit, reach 5 ft., one target. Hit: 3 [rollabl](1d6);{"diceNotation":"1d6","rollType":"damage","rollAction":"Shortsword","rollDamageType":"piercing"}[/rollable] piercing damage.

Longbow. Ranged Weapon Attack: [rollabl]+3;{"diceNotation":"1d20+3","rollType":"to hit","rollAction":"Longbow"}[/rollable] to hit, range 150/600 ft., one target. Hit: 5 [rollabl](1d8+1);{"diceNotation":"1d8+1","rollType":"damage","rollAction":"Longbow","rollDamageType":"piercing"}[/rollable] piercing damage.

(reaction, copy this separately)
Parry. The hobgoblin soldier adds 3 to its AC against one melee attack that would hit it. To do so, the soldier must see the attacker and be wielding its longsword.

I do have several notes too though. It's AC is wrong, platemail and a shield is 20 AC not 19, 19 would be splint mail and a shield. 
Also it has no way to use all of its items. Sometimes you'll see monsters that have both a shield and a bow, which you cannot use together, but in your case it's gone one step further and added a shortsword as well. Notice that the Veteran monster, that also has two swords and a ranged weapon, does not have a shield because that's too much to juggle, it takes a whole action to take out or put away a shield btw.

Also, the monsters HP is based on a formula, which your monster breaks. The normal hp of a hobgoblin, 11, is (2d8+2) or the average of 2d8 (9) + 2. If you want to increase it's health I'd do (3d8 + 3) for 16 hp, (2d8+4) for 13 hp, or (3d8 + 6) for 19 hp. The second and third formula assume the hobgoblin now has 14-15 constitution, the first is for the constitution it already has. The + health that's added (you fill that in "hit points modifier") is always equal to the monsters constitution modifier times the number of hit dice it has. That why you get + 2 on the hobgoblin for 1 con mod times 2 hit dice. Without changing it's constitution it's health would increase like this: 11 (2d8 + 2) > 16 (3d8 + 3) > 22 (4d8 + 4) > 27 (5d8 + 5) > 33 (6d8 + 6)
Notice how it goes up by 5, then 6, then 5, then 6. That's because every die that's added is worth 4.5 hp, so die 1,3,5 or such get rounded down to 4 and die 2, 4, 6 and so get rounded UP to 5. 1d8 is 4, but 2d8 is 9, and similar rules apply to weapon damage. 
    
The shortsword didn't have the monster's stats added to it. Wondering if that was intentional, I left the +1 damage off of the shortsword as if it was making a dual wielding attack WITHOUT the two weapon fighting style (most monsters get that automatically).
And you increased the monsters strength without marking that change in it's melee weapon attacks, you need to change +3 to hit and +1 to damage to +4 to hit and +2 to damage, (i've already done in the copy/paste comment I posted)

Also, the CR of 4 is WAYYYY too high. A CR 4 monster is a bit challenging to a level 4 party on its own, far far stronger than a level 4 character. Even with its improvements over the regular hobgoblin, including... resistance to bludgeoning piercing and slashing? Anyway, this monster unedited is a decent CR 1/2 or a weak CR 1. I'd recommend increasing its health to somewhere in the 20-25 zone, and making it CR 1. If you WANT it to be CR 4, it's health needs to be 60 or so and dish more damage (increase it's martial advantage to 3d6 maybe? and fix it's multiattack, a CR 3 veteran can take two swings of its longsword AND one with it's shortsword, which higher strength too). Without increasing its damage it'd need about... 120 health? And that would be one WIERD ass creature.

But hey listen, since I'm just bombarding you with notes all "this needs to be fixed that needs to be fixed" If you reply back and let me know what kind of stuff you want to do with this creature I can teach you how to tweak and edit this thing to just as pretty and polished as any non-homebrew monster statblock. I admire the spirit of wanting to make little twists on monsters that are already there. I'd encourage you to check out my Bandit Cutthroat, Bandit Swiftblade, Bandit Deadeye, Dwarven Gunner, Gnoll Warrior (that one's kinda boring) and more fun stuff like the BONE HORROR.

yeah i realize that now, but I just made AC 19 because its a crappy shield

hey sorry about all that, this is really just a template. change as you like.

some of my other stuff

https://www.dndbeyond.com/monsters/2018650-hobgoblin-elite

https://www.dndbeyond.com/monsters/2542435-mechanical-dragon