Your all forgetting that German pilots included, in all their kills, every battle period they ever fought in. For instance, British pilots in ww2 had their kills from the Battle of France (if they fought) as a seperate tally. So a pilot could achieve acedom in the BoF and then start afresh for the BoB.
For luftwaffe pilots, they inlcuded every war etc they fought in. Some pilots fought in the Spanish Civil war, so that was included in their tally
