For the countries without many members, could they build more elite armies, to offset some (not all) of the advantage given to larger nations? this would be like having archers that fire more accurately or have a preffered terrain ect. ect. ect.
Also, can the nations research things on their own, without much help, or do they have to gather together in group.
Almost the same as the last question, can we build doomsday/failsafe weapons so that if we are conquered, we can blow our cities to smitherines, destroy attacking armies ect.
i understand if you say things i don't like, about what i wrote, but it would be a good way of offsetting the larger nations.