A question for fantasy RPG map makers.
How much do you worry about "does this make sense"?

I have been working on my main continent map. World is larger then earth. Continent is about 8000 miles wide and 6000 miles tall. Goes from equatorial to arctic regions.

I found two posts here that go into a lot of great detail about human populations and density during the middle ages. Lots of good info I want to use. But it's based on our history, not fantasy.

Why are the different races where they are What explains the old tombs, temples, etc?

If the world is very old, lots of old stuff to your PCs to discover and explore, why is it there? or do you just not worry too much about the why?

Over the thousands of years that the world has been around the races have varied alliances and enemies, at one point or other everyone has been at war with everyone else?
One group gets too powerful and the others team up, or a plague, or a serious magic catastrophe (like a modern nuclear war) pops up and wipes things out?

Just curious what others have done with this or don't sweat it?