US IS ARMING their Army as Japan likely attacks nontheless.
Unlikely. The whole sequence that led to the Japanese attack heavily depended on things happening in OTl that aren't happening in this one. The Soviet Union, for instance, is not at war. The IJA will scream that going South is leaving the recently hot Mongolian-Manchurian area in danger.
Some of SU lend lease might go to UK - of corse, but I won't count 100% - and UK must be able to use it (UK does not grow men out of nothing)
Might? You bet. As to manpower, that's not an issue. The war you are portraying between the British and the Germans is not manpower intensive, being waged by the navies and air forces.
that germany can't pay is definitely a problem, but the SU might setttle on buying tech and weapons from Germany (Germany can produce for SU - THAT matter can be settled
)
It won't be easy, but its manageable ...
The heck it is. The Germans trusting the Soviets and selling them the rope with which to hang them (the Germans)? I'm using a very fitting manner of speaking used by a Communist leader, BTW. In short order, the temptation for Stalin to ally with the British against the real threat for the SU, Germany, will be too great.
And, in any case, if the Germans really do sell weaponry to the Soviets, then they aren't fielding it against the British.
The truth is that in that war, it's not as if the various players had many sane choices to make. More often than not, they chose to do what they did because the alternatives were at least as bad, if not worse - barring, of course, giving up, which would have been the saner alternative for their peoples, but maybe not for the health of the leaders themselves.