I see the criticism of Paulus' use of his PzK thrust to the Volga as unfounded. The left flank of the PzK was under heavy pressure & almost overrun. Expecting them to drive South into the city before the ID's caught up is not in accordance with the facts.
Up till 19NOV, Paulus did everything right. He got the cautious reputation at Kharkov, & first impressions take long to change. But his advance to the Don, Volga & management of the city fight was quite up to par.