[Stellan Bojerud (RIP)]

It is possible to combine several motivs.

Lebensraum + oil & other resources + secure the back + weak Soviet Armed Forces (judged from the performance in Finland) e t c

I think is is a fact that the Red Army lost several battles in the opening phase of "Barbarossa" because it was deployed for attack and not for defence.

The Germans lost "Barbarossa" because their Herrenvolk mentality. They were greeted as liberators, especially in Ukraine, but treating the Russians as Untermenschen the Germans turned a peaceful population into resistance fighters and partisans.

There was the Vlassow Army recruited amongst Soviet POWs, but for years the Germans could not decide to use it or not.

Given totally different politics, the Germans could easily have won "Barbarossa" just by treating anti-communist Russians well and supporting them to fight the bolscheviks. Germany had the posibility to transform "Barbarossa" into a Russian Civil War, but missed to do this.