[Franek Grabowski]

Well, there are tidbits here and there, suggesting he was actually a bit different person, see eg. account of Galland in Sicily in 1943 in Prien's JG 53 history.
Symptoms of collapse of Luftwaffe appeared in 1943, and in fact the poor performance cannot be explained by outnumbering of the Luftwaffe. In fact, researching a number of 1944 combats, I have noticed that Jagdwaffe had a numerical local advantage but still performed bad. Thus obviously, they were either poorly trained or had bad tactics or both, and this was area of responsibility of Galland. My impression is that Luftwaffe never learned how to fight in large formations against large formations.