just take Leningrad immediately but also "zurge rush" (lmao) Stalingrad at the same time. Like yeah okay I'm sure the Nazis (famous for Blitzkrieg not close combat) can handle two of the most intense urban warfare battles at once hundreds of kilometers apart without getting their ass owned.

taking Stalingrad wouldn't even cut off the oil either the Soviets had made preparations to ship Caucasian oil across the Caspian Sea to Astrakhan to keep the military fueled. It would have been awfully inefficient logistically but they would have been able to do it.