As pointed out above, it is the 3-1 that kills Germany, not Russia alone.
Russia is only on her own for the first 3 rds.
By rd 4 both UK and US are reinforcing Kar.
Allies to Afr on rd 2, reinforce fin rd 3, kar rd 4.
Also, Russia doesn’t need to trade arm for inf. Strafing is a VERY poweful tool that many people over look.
As Russia, I don’t need to take Ukr or EE, if I know I can attack and in the process kill more German inf then I’ll lose. Then you can safely retreat to Kar, place your reinforcements and repeat on the next turn.