Here ia a more realistic question for all of us, which propeller driven aircraft used in WW2 mostly in the more defining latter part of the war if it was never introduced or just to the point pulled off and ceased to be produced.
What would the lack of said aircraft have upon the effect of the war and redefining an alternate history?
Let me see if I understand your question.
For example, what if the P-51 had not been fitted with the Merlin and had stayed a Low level tactical fighter?
If the P-51 had not evolved I am not sure that the end result would have been much different. The Mustang did not see widespread squadron service in the ETO until early 1944. While the P-47 was a capable fighter in dealing with the Luftwaffe, the Thunderbolt did have a range issue. The P-47N model, with a 2,000 mile range, started flying in September of 1944 so it is possible that it could have been in squadron service by 1945.
So what does all this mean. By early 1944 the Luftwaffe was almost on the ropes. It was not a question of aircraft because the production rates of German fighters peaked towards the end of 1944. The problem was in trained pilots. German pilots flew until either killed or captured. The US would pull experienced pilots out of action and send them back to serve as instructors. This helped to prepare new US pilots for the rigors of combat.
Also the average US pilot went into action with about 300 hours of training versus the German or Japanese pilots who were lucky to get 100 hours of flight time.
All in all I don’t think it would have made a huge difference in the outcome of the war.
Regards
alfa6 ;>}
The Fairey Swordfish that torpedoed the Bismark's rudder was a game changer.