GRizz,
I like the ven diagram but it needs some suplimenting because it visually doesn't provide enough explanation of why the planes are where they are at. Been working with Waystin on something like this.....


The axis represent [so far what I think

] are the key attributes to a planes capability. The more area the plane covers the better it is at providing the pilot with options in any given situation he may come across in the MA. The P-39 is very limiting in what choices the pilot can execute at any given moment. Whereas the SpitXVI doesn't limit the choices much at all. By the way, something tells me HTC may have performed this exersise already and the results = ENY scores. I think Deadman was talking along these lines. This skips the need to use the exact performance cuves but rather to rate the planes from 0-10 basing it on the objective data, But also to account for things you won't find in the performance tables like how violently the plane departs, and how easy it is to recover from a stall. I just call that "Stall performance". Or whether the wings balloon in a dive, by just including that in the assessment of "dive Performance" etc...
All may have a different opinion on how many axis, and what the weighting for each is, but if you all do your own, the rank order should come out very similar.
Axis where you have an advantage in your plane over the opponent, are things you focus on in your attack/defense strategy. If the area of your plane completely engulfs the other plane, then he doesn't stand a chance.
The Spit is easy mode because the pilots choices are never limitted because the plane does most things better then most other planes in most situations.