[Franek Grabowski]

Many thanks for that!
Well, there are lies, damned lies, and statistics.
Given the gross numbers discussed an absolute accuracy is not necessary, as it is more about trends.
The problem is, that the numbers usually provided, regardless of their accuracy, do not shed a light on what really had happened.
For example, there are 2,927 the Few listed, 2,353 of them British. The problem is that a one was qualified as a one of the Few following only a single op flight, which he could make in the north, not seeing an enemy. Thus, the number does not represent the number of airmen involved in the hottest southern sectors. Also, I understand the number does include Blenheim and Defiant pilots but exclude gunners, which further muddies waters.
Then I have 1,259 pilots in July and 1,796 pilots in November. The losses were 510 (407 British), out of those ~450 Hurricane & Spitfire pilots. Total losses including wounded 710.
This means that approx. 1274 pilots arrived as replacement, 574 being foreigners not requiring extensive training. Thus 673 were RAF trained, which seems a bit low to me, as I recall the monthly output was about 500 pilots. On the other hand hastily trained pilots required further training in squadrons rotated on operational rest and may have been not considered operational and thus not put into the statistics. This is of course simplification but roughly shows the problem.
Then at the end of August RAF reported shortages of pilots and rotation of airmen ceased, so there must have been some problem which is not apparent from the above.
Also , I count 61 Hurricane & Spitfire squadrons which should have an establishment of 18 aircraft and 22 pilots, thus giving 1098 aircraft and 1342 pilots. Given there was approx. 600 aircraft in average, the question is if the latter is serviceable aircraft only, but still it should suggest a bit of shortages.
Of course, this must be collated with the German data, in order to create a broader picture, hence my question.