[Franek Grabowski]

Now this discussion tends to be ridiculous for a very simple reason. You discuss verified and approved victories and not claims. Therefore bureaucrats from RLM are to be blamed and not pilots. Another point was well proven by '6' - indeed, in similar environment accuracy of JG 2 and JG 26 was similar. They were accurate over ground, where wrecks could have been counted and they were ridiculous over sea, where there were no wrecks at all. Discrepancy between JG 2 and JG 26 is just only because the former flew mostly over the Channel while the latter in the St Omer area and German clerks had just enough time to verify every claim submitted (with various results though).
That said I consider RAF late war victories most accurate, both due to quality of pilots but also methods of verification.