I think Hunter's Mark should be a cantrip, like booming blade. Cast with a successful attack, scaleable extra damage based on weapon type used in casting,1d6 lvl 1 til, 5th lvl 2d6, 11th lvl 3d6, 17th 4d6, and the inflicts a bleeding condition for one hour, making it easier to track the marked target if they flee combat. Still requires concentration. This cantrip is only available to Rangers.

Then create a Trackers Mark cantrip for advantage on survival checks for hunting prey, whether that be a deer or a member of a raiding party you spotted earlier. Last an hour, concentration.

With 3 of the later class features being based around HM it would make more sense for rangers to be able to not concentrate on this since they also have so many concentration spells. Unlike a lot of people however I believe that replacing effect of Relentless Hunter to “Hunter’s Mark no longer requires concentration, but you can only have one creature affected with Hunter’s Mark at a time.” would be a much better and more balanced option. It would force a 13 level dip into ranger just to get that extra damage but that’s most of the build at that point, it gives you an option but not a good one and it makes rangers so much better off than they are now.

level 11 paladins get to add 1d8 radiant damage to every melee attack they make for free.  Divine Favor is not concentration.  trust me, Hunter's Mark not being concentration would be far from broken.  in fact, lets use the exact same comparison you did: Level 11 vengeance paladin dual wielding scimitars with the Two Weapon Fighting style.  Cast Divine Favor (not concentration) and Hex (Oath spell).  3d8+6d6+3d4 damage per turn, for exactly the same average damage as your example, possible by RAW, without multiclassing, and one level earlier than your example.  

What level do you get hunters mark for ranger with 2014 rules?

Quote from belarbearshoulders >>

What level do you get hunters mark for ranger with 2014 rules?

It's not granted automatically, but you can choose it as a known spell when you first get access to spellcasting, which for 2014 Rangers is level 2.