If Dwarves were "realistic" the mere fact of going out into the sunlight should blind the fuck out of them and they certainly shouldn't look like short humans with beards. To say nothing of even trying to explain the biological implications of Elves being nigh-immortal. You're fighting a losing battle by trying to bring real-world biology in a universe with 0 concerns for it.
Sentient trees that sometimes walk, Balrogs, Ungoliant, friggin wizards who actually are angels, that's all fine and well within the bounds of science we accept in our fantasy universe made by a linguist who didn't give two fucks about such things, but black people? Outside of their Designated Black People Zone? Na, that's just going too far son. My immersion, it is shattered.