With respect to the F4U's...I have 2 thoughts/comments.
1) If you fly the arena's, most of the f4u's you see are actually -1A's. Yet the charts indicate otherwise - both the -1D and the -1C show greater "use" than the -1A. I'd hazard to say that most of the reason for the discrepency between how much you see the -1D and the -1A in the arena compared to their indicated use is the use to which the aircraft are put to in the arena - A handful of guys running suicide missions from a CV two miles off of a field are going to greatly increase the number of deaths in the -1D, which is going to exaggerate it's "use" in the charts above. Meanwhile, exactly the opposite is true of the -1C. It's status as a relatively poor performing fly perk plane with a brutal armament package means that it's not nearly as common to see as the chart would make it appear - but the guys who do fly it are good enough to get put those massive guns to good use, racking up lots of kills in a shorter time - which again exaggerates the "use".
So while the reality is you see more -1A's than both of the other too combined in the arena, it doesn't appear so because fewer deaths (and kills) are spread out over a much longer (on average) sortie. Ideally, the total amount of time players spent sortieing in each aircraft would be a much better measurement of "use", although I realize that Lusche had to work with what he can get, and if that's available, I've never seen it anywhere.
2) And with respect to the assumption that the K/D ratio for the -1C and -4 as compared to the rest of the plane set are good proof that they should be perked, that is a case of "statistics can prove anything you want if you start from the wrong assumption". The biggest reason that they have such markedly higher K/d ratios than other aircraft is not because they are so much better planes which proves they deserve their perks, but because they are perk planes in the first place and those that fly them are both more experienced, and more conscious of not losing the plane BECAUSE of the perk. If you perked the C202 or the Spit IX, you'd see a sudden and dramatic rise in the those aircraft's K/D ratio too.