The thing I have about the Japan/Russian scenarios is that few of them make any military sense from a Japanese point of view.
Lets ignore realities of previous Japanese/Russian skirmishes that ended in the Japanese getting their butts kicked and assume a Japanese assault on Russia was successful they would have multiple hundreds of kilometres of frozen tundra to get through just to capture anything useful, if you think the Russian Front was miserable from a German point of view I cant imagine how bad invading Siberia would have been from a Japanese perspective.
Now to jump back to some facts.
Of the 14 Eastern divisions transfered West between August and December 1941, two were under strength cavalry divisions, 3 were Tank/Mechanised divisions that had only been formed in April 1941, the rest were Rifle Divisions of which three arrived in August and September and were sent to 11th Army defending the southern approaches to Leningrad or 7th Army defending the far north against the Finns.
Only six rifle divisions arrived in October and only four of these went to any Army that could be even remotely linked to defending Moscow against Army Group Centre.
Over all their combat performance was regarded as "average".