I agree sir. What Japan wants is those 20 pieces out of its hair. If it can destroy most or all of them, that’s great. If they leave for Moscow–that’s good for Japan, but not for the Axis after G7, if the Russians can survive that long.
If they stay in the east the whole game, they still aren’t a threat–but Russia holds its territory. Japan needs like 6-8 inf and some planes to ward of that stack. If they stay in the east, that’s good for Germany but not that bad for Japan.
Japan can do a lot of other things, like tie up or destroy UK/ANZAC fighters that are crossing asia heading to Moscow, or stratbomb Moscow from behind. Russia can’t, its too weak and under pressure to accomplish much other that survival.