I think 4 players would be ideal for the global game that way you don’t have players losing interest. Axis is obvious G & I, then Jap by itself. Pretty much splits were the maps come together. Allies might be cool to split the two theaters also. 1 play Euro side (Russia, England/Canada/Africa, France, E US. The other play China, W US, India, Anzac. Of coarse you can work together but have your own agendas (NO’s).
Even AA50 is fun this way, and it keeps it more of a global game. I would not treat it as totally separate theaters, you still need a certain amount of cooperation. Russia will find itself aiding China/India (protecting its interest), or given the chance Jap will still invade Africa/Russia etc.
I’m not sure if each power will still have its own turn in the global game, or if there will be powers taking their turns together like China/US in AA50. Larry has hinted that the UK player will most likely play France I thought talking about its fleet and what not? Maybe the rules will be somewhat vague (imagine that) and allow players to do as they feel fit, as long as each power still gets its own turn.