What he's explicitly asking is if there's any pre-war PODs that would lead to the Soviet Union doing better...say, by making it so the Red Army handily crushes the Nazis in the opening battles of the war, then rapidly counterattacks. The loss of literally millions fewer soldiers at the beginning of the war would seem to go a long, long way towards making up whatever "soldier deficit" you imagine would exist compared to the Red Army needed to push farther West.
I saw a pretty interesting TL once where Poland does much better, messing up the Germans some.
Mmm, the might butterfly away Barbarossa though...