There were some pilots who shot down over 100 planes on western front. No one got over the 200 mark in the west though. My fav. Galland should be one with high score in the west,
However I had a look over the scores yesterday and noticed that if we do not count Finland into same group with Allies (although she had a small war with Germans in the Lapland), then the highest allied ace is the Russian Ivan Kozuhedub. That makes Top 116 pilots "the enemies" and top 108 are Germans. Rudolf Trenkel if I'm not mistaking got 137 kills in the west, Werner schroer should have gotten 102 kills in the west, Galland 104 and I think night fighters scored high against western-allies.
And Americans flew even on the Eastern-Front. Not that I'd think much of USAAF though...
352 kills (and Barkhorn's 301[Dreihundret und zwei
] ) are still amazing. Moreover since Harmann fought since '42, where Luftwaffe was all the time losing the edge to Russians and Russian air force was picking up power.