There have been a few mentions of the Flying Tigers of late. What if they had formed from 1937 when Chennault got to China? Perhaps in the 4 years between then and PH the AVG could be used by the US to gain crucial air combat experience, much like the Legion Condor did for Germany in Spain. Even if there were less than 100 planes on strength over 4 years hundreds of pilots could do tours and then re-join the US forces.