You completely missed my point. The Defiant was a bad design (or a bad spec or both). It got canceled as the result of miserable combat performance which highlighted the major flaws of the design (or the spec).
Again, missed the point, but your factual information is off as well. Most of the Buffaloes were used (unsuccessfully) by the British in the CBI. In your little summary you also seem to have forgotten about the
USMC F2As used at Midway among other places.
But that is again, beside the point. What I was referring to (I thought it was obvious) was that combat experienced demonstrated that the F2A was unsuitable - whether in Rangoon, Singapore or Midway. But mainly RAF combat experience. I didn't mean literally every case meant the plane got more guns or etc.. That tended to be reserved for the most successful designs.
This is what I was saying earlier:
"very often aircraft made it through all the testing and acceptance phases, got into combat and were found to be extremely unsuitable for the intended mission when faced with actual enemy aircraft. Example I cited above such as the Defiant, the F2A and Me 110 were either quickly phased out or given a new mission (Me 110 converted to night fighter) or like the Ki-43, they were 'sent back to the drawing board' with fairly significant changes made."
I don't agree with you. Not all changes were done in the factory for one thing.
More generally, the P-38s most serious teething problems (dive compressability, cockpit heating etc.) were continuously being complained about in the field - Lockheed tended to deny the problems and even sent Charles Lindburgh among others to smooth things over with pilots and teach them better combat techniques. But the fixes came later.
S