Any one that can take on 3 guys in a p39 and win is not average. Then again, its is all relevant. Who were the three you took on? I am just saying that dieing to some one better than you in a p39 after giving him a work out could mean a lot more than killing 3 zeros in it.
God no, I don't think I've ever won every 2 v 1 in the 39, definitely 3 v 1. But I find to learn more when I jump my 39 into a bunch of gang-bangs, there's been times though, that training in my 39 has helped me survive gang bangs (of course, with many pieces missing still haha)
Wouldn't it make more sense to 'train' in the aircraft you plan on flying the most?
All aircraft 'tick' differently, but there's always definite advantages in each. When you find that one plane, where you have no advantage except the skills on your back, it's a perfect "trainer" for the game. If I ever become a terrible gunner again, or I quit for a while, first thing I'm gonna fly when I get back'll be the P39Q.