I've always referred to them as the "Big 4".. Nik/Spit9, P51D/La7.
Of the 4, only the P51 isn't what you could call dominating. The B is in the same boat as the D, except it has less firepower and worse visibility. On the whole, an La7 will absolutely destroy a P51 in A2A. The N1K/Spit9 is about a draw.. the N1K turns better, the Spit9 does most everything else a tiny bit better, firepower is about the same.
But seriously, going back to Beetles "point" or argument, or observation, or whatever. Ok, so the "Big 4" are all pervasive. Not going to argue that, at any given moment I'd say they make up 50% of the planes in the air, and everyone flies them. They also have a tendency to "inflate" ones "ability" in an A2A fight, thus inflating stats. So I still think it is true that most people in the top 100 for fighters rely on their plane to get them there, and would not be there if not for that.
I will say that numbers in a plane does not equal time spent in the plane though. Last tour I had 60-odd kills in a Chog in 3 sorties, and 60 odd kills in a n1k2 in about 6-7 sorties. The rest of the month I spent in 190s mainly. So did those 10 sorties inflate my stats? Certainly, although I can't say by how much.
Just doing some "stat-research" and maybe some interpretation, on my own. Lets look at Kappa, since he finished 1st in fighters last month. Overall K/D of 14.5, K/S of 5, K/H of 13.7, Hit% of 19%. Ok, Hit% is tough to "game".. so he's a good shot. Figure even if you shoot 60% on vulches, you arent vulching all the time, so to hit with nearly 20% is good. K/H of 13, pretty good. That stat is kinda tough to "game" to, imo. You'll get a super high K/H vulching... but nobody vulches all the time.
The K/D and K/S are good, but here is where I'd make Beetles "argument" that they are strictly plane-related. Looks like he flew 3 planes this tour, the P38, the P51D, and the 262. Just going off the "stat" pages (which don't count augers and such as deaths, so they'll be a little higher than what the "score" pages give him).
K/D in the P-38 is stellar.. 13.73. Not many people could get a K/D that high in a P-38.
K/D in the P-51... 29.5. Why do you think his K/D in the P-51 would be higher than in the P-38? Especially since it would appear that the P-38 is his "main" ride... wouldn't it make more sense to assume he's be more "skilled" or "better" in the P-38? That is kinda puzzling.
K/D in the 262.. 34.6. Again, how strange. He had about 1/3rd as many kills in the 262 as in the P-38.. but his K/D is so much higher. I think he is a 262 ace and he's been holding out on us with his reputation for flying the P-38.
I can't look up the K/S value for individual planes, but I'd be willing to bet he got more kills per sortie in the P-51 and the 262 on average than he did in the P-38.
But what do you think would have happened if instead of flying the P-51D and the 262, Kappa had gotten an inexplicable urge to fly the 202 and Spit 1. Do you think he would have finished #1 in fighters? I think the answer is pretty clearly not, but feel free to tell me why you think I'm wrong.