Ace= 5 victories?

The commonly accepted understanding is that the title of ace went to a flyer with five victories. I seem to recall that one nation (France?) first used the total of ten for such status, but later fell into line with the other countries.
A few years ago, I corresponded at length with Stewart Taylor on the question of Canadian aces.
He used the number four, not five, for acedom. His rationale was that in 1935, the German Reichluftfahtministerium (spelling) presented Fred Hitchens, History Dept.,NYU, with a list of all their WW1 Kampffliegern they considered to be aces. The listed started with #1 (MvR) and ended with #458 Ltn.d.R.Gustav Wember (4 victories). Taylor thought that this was the first time that their WW1 ace list had been presented to the Western world, and that the German authorities were using four, not five, as the standard for ace status.
Comments?