Paulus was a staff jockey, plain and simple. A very good staff jockey, but a staff jockey. He had little command time throughout his career, and had never commanded anything near as large as Sixth Army. Aside from doing one of the final drafts of Barbarossa, Paulus’ major contribution earlier in the war was spying on Rommel for Halder. Sort of a German version of Omar Bradley vis a viz George Patton.
Paulus’ operational plans at Stalingrad were pedestrian, unimaginative, and showed a total lack of understanding of how to handle armor. His refusal to break out early in the Stalingrad siege without a direct order from Hitler, as well as an almost complete lack of interest in his troops once he surrendered shows moral cowardice on a grand scale. And none of that is Reichenau’s fault.
The contra argument is that with Reichenau as a mentor at Army Group South, Paulus would have had firmer direction from above which was lacking in Operation Blau. And that’s what you’re supposed to have a Army Group C in C for.
Glantz paints a different picture of Paulus as army commander anyway. But we can discuss that next year.