D&D 5E (2024) WotC Should Make 5.5E Specific Setting

[CreamCloud0]

None of the places have to suffer. A nation could have multiple species in them.

In my cousin's setting the Rebellion were mostly Orcs and Tieflings who shared mistreatment by the Empire..

dividing up the species into 'kingdoms' i'd personally go with:
humans, tiefling and aasimar.
dwarves and goliaths.
orcs and halflings.
elves.
dragonborn.
gnomes.