The contention had been that the Germans had been brilliant in defense in the latter half of the war and they only lost because that brilliant military was overwhelmed by sheer numbers in men and material.
But this is the usual line of the German Generals.
In part it stems from the needs of NATO who were needed a "clean" wehrmacht so they could rearm Germany; they were also going to face the Red Army whilst outnumbered if the Cold War turned hot so wanted to tap into the experience of the people who had just been fighting the Red Army
It also conveniently ignores the idea that numbers did not help France in 1940 or Russia in 1941.