Having played 2 times, I totally confirm that Soviets have been for some reason nerfed.
Actually I'm quite disappointed with this DLC (my fault that I probably was not so attentive to DDs), I expected some sort of mechanic to simulate disaster during first months of Barbarossa. Something that might force Soviet player to not be able to deploy all forces on border (if played via historical Stalin focuses) and force to deploy in 3 separate deployment waves (as it was historically), so Germany is able to crush Soviet forces with having serious number advantage in any given place and allow for tremendous encirclements.
In order to simulate history you need to make sure that by 1941 Soviets have MORE factories than Germany but more quality based army and tactical advantage, so only way for Germany to win in this war - is to quickly capture as many factories as possible, create encirclements and destroy as many divisions as possible, to even the odds.
Yes, I understand that some tactical decisions that force bad decisions on players (like bad deployment) might be seen as arbitrary, but this is something that good game designer should think about and implement wisely.
What we have now in MP is that German player just steamrolls Soviet if fight is happening one on one, not in blitzkrieg, but in a long run in a war of attrition! This is just ridiculous.