Blizzard already has the capability as well:
Alexstrazsa is basically a female Blood Elf body that's modified, and Y'sera too is a modified night elf (though I think her bone structure or w/e is blood elf), and ofc Nozdormu is a modified High elf/Night elf.
This shows us the amount of variation they can do with races while still having them look like a member of that race.
Y'sera obviously looks like a Night Elf, just unique.
Alexstrasza obviously looks like a Blood Elf, just modified skin/eye colors.
Nozdormu is obviously a High Elf, just modified/unique.
It shows that you can change the proportions/looks drastically and still keep the essence of a look. Blizz knows how to do this.
For Nozdormu's look they can easily remove all the dragon related regalia/tattoos and give a more "normal" looking face/size. Boom, male High Elves that look different from Blood Elves but are still looking like a High Elf.
Just like how Y'sera is a different kind of Night Elf both different from playable Night Elves and Nightborne.
And no I do not mean because of their horns or dragon shit like that, (cuz I know some dumbos will go "BuT tHeY r DrGnS!")
They are obviously choosing to look like members of the respective races with their forms. Just like Kalec who basically looks human.
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Better pic for reference:
