FLYBOYJ
"THE GREAT GAZOO"
Read the "Forgotten 15th" I think your mindset is affixed to operations from England, read about P-38 operations from North Africa and Italy.It's the P51 that was able to protect the B17's not the P38 and the P38 was around a long time before the P51 and had slightly more range. Lastly, it mattered less if a different variant was required to perform a different roll as there was a lot less aluminum available as opposed to wood, and a lot of piano makers with nothing better to do. As for climatic problems, again, just build another one if they lasted in combat that long.
The Aluminum shortage was a myth - there was plenty to go around.
The Mossie was a great aircraft and there were some things it did better than the P-38, but as a long range fighter, the P-38 was more suited