Any game that offers this feature?

I have been playing Rise of Nations (golden edition) for a long time. I know almost all the tricks and codes, including editing the population rule to allow for whatever desired population. However, I just cannot find a way to have this feature added to Rise of Nations or maybe available in a nother war strategy game.

I want to keep the native population of a conquered city. For instance, if I am a Turk and i entered a Russian city, I want to be able to allow the original population to continue inhabiting the city instead of watching my soldiers running behind civilians and butcher them. I either have to form a peace with Russia to allow its civilians to exit the city, or they will be dead once the city is assimilated. I want the original population for instance to continue living in the city, build their own church, architecutre....etc

Basically summerized, how can you maintain a minority? In the Rise of Nations, there are no minorities, all must exist the city or be dead. Any code to edit that? or any better game?