About the representation of races, it's interestingly problematic.

Potter world is clearly an old-European fantasy construct of witches and warlocks, complete with brooms and pointy hats. If you integrate the characters, do you need to integrate the different traditions of magic and imaginary-figure notions? Would an American Indian conjurer ever go to study at such a place as Hogwarts, on some sort of exchange-student program? I'm not sure how long the Potter characters are supposed to live, which also complicates the representative population question. Clearly they aren't immortal, but do the demographics run parallel with Muggledom? Or is there a timelessness/fantasy lag so that things need to seem a little behind the everyday clock? I don't know, but it's a problem of fantasy that things get oddly fitted, the rules aren't quite clear, it's messy, and depends on a kind of preponderant versimili-sort-of-itude. Like the problem of cartoon dogs Pluto and Goofy.