P-63 should be added because people will fly it.
The whole usage argumant is so flawed its hardly worth going back over (arado, Ta-152). P-63 qualifes under the rule.
Aces High is a great test bed for how planes matched up and performed relative to each other in ways THAT NEVER HAPPENED IN THE WAR. P-51s didn't fight Corsairs. But I don;t here you guys screaming about wartime acuracy when it happens.
Yet it's fun to see how German planes match up against Japanese planes, and British against American, Etc...
The P-63 is a very interesting plane because it has the potential to be the best All American dog fighter of the war, something America wasn't interested in, in late 1944. It was interested in Long range escort fighter bombers. Th eP-63 no long matched the mission.
It's value in the game is: It would be fun to fly, would get more use than many hangar queens, and would prove once again that the American air-corps brass were a bunch of knuckleheads.
Saxman and the other WWII history book snobs never take that into consideration. Instead they pound the table for hangar queen after hangar queen, because they were relevant in the war at some point in 1939. Al lof which is just an excuse to flex their trivia muscles on the internet.
Vinkman