Cromwells and Churchill's had 75MM ROQF. It could fire the same ammo as the Sherman tank, but this was mainly done for the HE shell. The british used the APCBC round alot on their cromwells and Churchills, and it had higher speeds and also better armor penetration.
The 75MM gun firing the M61 APCBC shot could penetrate 93MM armor at 1000Meters and 82 at 1500. Imo, cromwells should be allowed the standard AP shot of the sherman, and a few APCBC rounds. This would give some better performance. In FH1 you could atleast damage panzer IV's and StuGs. In FH2 this issent possible, with gaint losses as the result
And what is happening of the 6PDR cromwells? Their where still plenty present in Normandy