A little known fact: in Dec. 1941-Jan 42 some 80% of the tanks-—and most of the heavy tanks-—defending Moscow were British and American. The best Russian fighter plane of 41-42 was the P-39 Airacobra, a plane the US didn’t even want.
You have a reference for that?
In 1941 the Soviets had by far the largest number of tanks of any country, most of which were produced in country.
It seems really odd to me that in early 1942 huge numbers of British and American tanks would be in Russia. The Brits had their hands full elsewhere, and the US had just gotten into the fight, was desperately expanding and needed all the armor it could get for its own forces.