Historically it would be like a nightmare for any German pilot, flying B109G6 and FW190A8's vs Mustangs, Thunderbolts, Typhoons Spitfires Bombers of all types etc etc
First day of the scenario would also be boring - for the Allies, and hell for the Luftwaffe - for both 190's who actually showed up at Normandy beaches the 6th of June:D
Allied side flew thousands of missions the same day.