the "flying fortress" named so because it has so mnay guns and with overlapping fields of fire, it didnt need an escort.
In theory great, in practise not so great.
Bomber command in the later years were bombing more accuratly by night than the us by day (thanks to technology of course). How can you realistically escort bombers at night? very difficult.
The P51 was meant for long range, it could handle it. Spit was short range. Though could of gone long range IF needed. But like agreed, if its not broke why fix it.
No doubting the 51 was a superb if not the best escort fighter, and a huge morale booster to friendly bombers that saw it.
And when i say "any" fighter, in general i was reffering to the obvious ones, not things that are out dated or obsolete by that time. Error on my part, i could of worded that better