Britain would likely field different aircraft by 1942, while American and Japanese designers would not have observed three years of European war. Combat feedback influences requirements, tactics, and which prototypes receive priority. Removing the war's 1939 start changes the development path before the Pacific conflict begins. Historical 1942 equipment cannot simply be moved unchanged into a timeline where its formative events never occurred.
Notable Point · 3:09:44-3:10:24
Why a 1942 war would not use the historical aircraft list
Delaying the war changes both which aircraft are ready and the combat lessons that shape their development.