Von manstein knew. At the command conference he will be the only one to forcefully argue to continue the operation. He senses that he has the Soviets on the ropes.
Von Manstein was the finest General of the war on any side. His brilliance allowed the Germans to defeat France in six weeks. The Kaiser couldn’t defeat France in 4 long years. The Wehrmacht was doomed the moment Hitler attacked the USSR. It transformed a European war to a world war which Germany didn’t have the resources or men to win. The Kreigsmarine, other than U-Boats were not much better than a 3rd rate power. The Luftwaffe had very little strategic value during the war. Most of their planes were designed to support the army. The fact that German soldiers prolonged the war until 1945 was remarkable.