P-39

I have read that the usefulness of the Bell P-39 was greatly decreased
by certain decisions made by the USAAF before it went into production
in the 1930s. Chief among these was the deletion of the
turbosupercharger, but the shortening of the wings also had an effect.
The question is, just how much more effective would this plane have
been had these changes not been made? Would it have a much greater
climb rate and been more effective at high altitudes? Or would it
still have been pretty much of a bust as a fighter/interceptor?