An intersting historical fact is that when the Luftwaffe captured an intact Spitfire they first tested it in its original state. But then their engineers wanted to examine the Merlin in detail, so they took it out and fitted a DB605 to the Spitfire, creating the "MesserSpit" hybrid. In trials, this DB605 powered version outperformed the original Merlin powered Spitfire.
Also, the Merlin powered Me109s used in Spain also outperformed the DB605 powered originals.
The inference could be that both airframes were mismatched to their engines - but I expect the story is a lot more nuanced than that.