I would keep scenarios generic and not identifiable to Real Races Past or current. Its an association Game Developers avoid like the Plague, same goes for Religion. Both those topics can ignite Huge Bush Fires, and nasty vitriol as inevitably someone takes it to heart, ignoring that it is a game. Its then downhill from then on to obscurity.
Sid - aka Civilization Series - takled Religion very very carefully for Civ IV. They wanted to use the actual names to give a semblence of reality to the backdrop of Religion in the game. However, they were very very careful to ensure that each Religion was dealt with in exactly the same way, and no one Religion could be seen to be omnipotent in its own sake. Even then, they got 3 months of grief after release from those whose Religion was not included.
Humans are funny folk, and when it comes down to it, very illogical and emotional.
Just a thought - I'd hate to see all your hard work be immersed in a sea of controversy. I would suggest that real Races have a backdrop that looks to the future out there in the Universe and does not mention anything to do with their past - the latter is a short road to Grief from the silly nit pickers.
I think you're right to an extent, but it still needs to have a real world grounding. As long as you don't have something like the UK race referring to French as Cheese eating surrender monkeys
Or somesuch, I think you're fine.
My welsh Custom race for this mod will make reference to the 700 years of control the English have had over us, and how in the late 20th century we began to regain our own political independence.
Nit pickers only cause grief if you pay them any notice, and they don't have to use the mod if they find such minor things wrong. If they like the mod but not the history, it's easy enough for them to change themselves.