In response to Umbridge being threatened on him, Dumbledore finds out that that due to an old treaty, hogwarts doesn't in fact have to listen to the ministry or the govenors and is sovereign. So, he decides Goblins, Centaurs, and even house elves are allowed to enroll at hogwarts. Of course also werewolves and vampires. Even have Olivander relocate to hogwarts to get around British laws on who can own a wand. How does everyone react to a bunch of children/teen people of a variety of races and backgrounds joining hogwarts? What does it do for the war.

Ideally a fic like this would avoid fanon and even canon cliches. House elves don't all love slavery, Goblins do in fact have an entire culture other than the bank(which is not central to their culture, just that's the only way humans ever interact with them). Centaurs in the forest love divination but not all do.