Do you care what the other 'half' is?

[Man_Over_Game]

The Half Elf Variants in the SCAG book gives a lot of inspiration on this exact topic.

You can be a High Half-Elf, or a Wood Half-elf, but you have to sell something to do so.

What really helps is that the Half-Elf is fairly mundane, and the thing you sell are the two skill proficiencies (for something like getting the High Elves' cantrip+weapon proficiency). Everything there is mundane.

For something that's already a hybrid, like the human-with-holy-spirit Aasimar, I'd probably say that they couldn't merge well, and mechanically trying to balance the class out when they already get level 1 flying for a minute is pretty difficult.

I say, if you want Elven Accuracy, you probably need to be a boring elf like the rest of them. That's part of the catch of the feat. Otherwise, someone, somewhere is going to be harassing you about how his variant human-half elf is totally balanced because he gave away all of his skills and languages for level 1 Elven Accuracy leveling as a Vengeance Paladin for his stupid 3d20 attack rolls.