Using fantasy for representation is silly. Why do we play these games, answer mostly to role-playing. Role-playing only works is if the characters are realistic. Make setting as fantastic as you want, make the story as fantastic as you want, but the characters have to be believable to be interesting. So to take the fat body idea, fat bodies for PC are not believable, we are running across the world and back fight 24/7 by necessity we need characters to be in shape. When it comes to things like race, if you make a country for you world it should be homogenous, and if it's not you need to provide a reason why otherwise it's not believable.
In other words, representation makes stories worse.
Lmao what kind of backwater country has never experienced some level of human migration or societal fragmentation at any point in thousands of years of history? The concept of a perfectly homogeneous society is a recent imagination based on an idealization of the nation-state model. How tf did these perfectly homogeneous societies trade with other perfectly homogeneous societies and acquire goods from far off lands without somehow acquiring characteristics and members of other "perfectly homogeneous" societies?
