Another team specific rule which could be clarified is what happens if your team-mate decides to deadbeat. Do you take control of their armies? If it's 3 players, do they get split between both remaining players? Do they go neutral? Do they take on a life of their own and spontaneously massacre all ...

Here's an idea that I'd make if I had any skill at graphics: Airports.
Each 'continent' would be represented by and based on a major airport i.e. JFK in New York, Pearson in Toronto, Heathrow in Middlesex, Fiumicino in Rome, Haneda in Tokyo, &cetera. The territories would be the various parts of the ...

Two ideas, related themes, neither using typical geography:

1. The human brain. The territories could be the parts of the brain i.e. neocortex, frontal lobe, brainstem, hippocampus, nerual node, &cetera. The 'continents' could be areas grouped according to major functions i.e. vision, speach, motor ...