It would be fun to include the Chinese Communists as a special guerrilla power that would give the Soviet player a nice break from the drudgery of mounting a possibly futile defense of Moscow. I have a few thoughts:
-In guerrilla fashion, the Chinese Communists may place units in Japanese territories, if they are occupied they act as blockers for Japan’s next turn and if empty they change ownership.
-During combat, all surviving guerrilla units “hide” after the first round and the battle ends. In essence this borrows from 1914’s contested territory concept, and the presence of guerrillas sabotaging production can be simulated with Japan collecting no income from the territory.
-Communist forces may never move into a territory occupied by any Allied unit.
-In order to generate some income, the communists should get a token NO for Soviet support, maybe 2 IPC as long as any Russian territory is linked to any Chinese (Nationalist or Communist) territory.