Going into 1944, and certainly by D-day, any comparisons of fighter airplane quality vis-vis allies/German starts becoming foggy.
I have no doubt the Hellcat would have performed well but the simple fact is Luftwaffe losses and fuel issues were starting to disintegrate what was once a fine fighter arm. German industry could replace the aircraft but not the Pilot quality and by the middle of 1944 they were putting up kids hardly trained to fly let alone fight.
It created a murky picture of late war aircraft comparisons that I think still exists somewhat to this day.
Just thought I'd throw that into the discussion.