i start with artillery and a bomber in the first 2 turns (maybe even 2 bombers if i feel agressive/lucky).
No tanks.
I will probably send the existing tank/mech east for fast help in China or Siberia.
Artillery (obviously) because Russia has a lot of infantry, so that doubles their (counter)attacking power cheaply this way.
These cheap units are easily combined with the power and range of the bomber, which you won’t need to lose. Tanks are great, but also expensive and when they take a territory, you’ll probably just lose them in the following german assault there. pity for the money.
A bomber costs double as a tank but you won’t lose it (and it has a higher attack), so in the long run i think you got a good deal.
they can also be used on the other side (they can even reach Yunnan from Moskou in 1 turn, land in Sikang or India).
Expensive unit, but great reach.
Edit: later on i’ll also consider a tactical bomber