The problem isn’t one of making the game “more historical,” but into a game about World War II in some way. The fact is, in WWII, the Japanese and Russians were not at war, while in Axis and Allies, if you are playing to win, Japan will likely conquer much of Russia. This didn’t happen in WWII solely because of a piece of paper, but rather because Japan would not have been able to conquer Russia.
Yes, give the players options. But why make the BEST option also one that would have been 100% impossible in WWII?
I’m all for abstractions, such as all units costing the same and functioning the same for each nation, units not representing real world units in a 1:1 ratio, etc. By all means, give the player an option to invade Russia as Japan- but make it so that, like in the real war, this course of action proves to be extremely difficult- NOT the best strategy.
Same thing goes for America and Britain completely ignoring Japan. That would have been absolutely insane, yet in A&A, it’s the best thing the Allies can do. Just imagine it… “Well, we got Berlin. Yeah, Japan owns the entire world outside of North America and Europe, but we have Berlin!”
Maybe we need an altered “Economic Victory” option. If any one Axis power gets 20 IPC more than they started out with, automatic victory for that Axis power and loss for the Allies (and perhaps the other Axis power, if played by separate players). Or with victory cities, give Japan and Germany their own unique targets. If one Axis power gets their targets, they win.