How was Noah even able to tell that the Protagonist is a human? Humans and demons look exactly the same in this manga and the difference between elves and beastmen is also just a miniscule difference in the ear shape. At this point it doesn't even feel like a race dispute but just a random national dispute instead. With this little difference between the races they would've already intermingled to the point where nobody could tell ones race (unless they can't have children with each other (or from a biology standpoint atleast not children that are able to reproduce)).
Tl;dr: whytf do all the races look pretty much the same?