This is the fundamental problem caused by the archaic “Capture the Capital” rules: however you try to avoid it, the game always comes down to the Axis trying to capture Moscow before the Allies bring their combined industrial muscle to bear.
This makes Moscow the inevitable prime objective for Germany (except perhaps London, which must be achieved without Japanese help), and as the above posts suggest this is only likely with Japanese help from the east.
No matter how many territories Larry places between Moscow and Manchuria, or how many false diversions towards “Victory Cities”, the C-t-C rule will always bring those Axis armies towards Moscow like a giant magnet. The huge benefits of closing down the Russian economy are still so vast that any other Axis strategy is completely insane.
This is why so many house rules delete the rule in favour of a power being able to collect money from every territory it holds regardless of capitals, and produce units as long as it has a factory remaining. In other words, the Axis must close down the Russian economy by stages, capturing all it’s industrial centres in turn, rather than the inevitable drive to Moscow.
There should in fact be 5 such centres in Russia, with Kiev (west Ukraine) and Chelyabinsk (Novosibirsk) having factories and respectable IPC values. Japan can cast envious eyes on the Siberian factory, but with the race to Moscow no longer the key to everything, a long term Pacific adventure may be more rewarding.