I like Lazs idea, but it honestly doesn't workable to me. Seems to me that most people aren't interested in flying certain planes, as long as they can get easy kills. The Spitfires (because of good turning and great cannon), N1K2 (see above), La7 (best plane in the set), and P-51D (slightly worse overall than the La7, but better visibility) provide the average pilot with a relatively easy way to get kills.
Dividing the arena up would merely cram 95% of the MA population into an area 1/3rd the size of the map, while the remaining 2/3rds go unused. This will (in my opinion) lead to even greater polarization in the plane-set, since it will be either use a good turning plane (i.e. N1K or Spit) or a really really fast plane (La7 or P-51). Anything in the middle won't have enough room to sort of fly around the edges of furballs and bait people (like you can do now, sometimes- of course sometimes it backfires and you end up in a 15 on 1). The early and mid war 'areas' will stay empty (comparitively) because the kills won't come easily enough for people to want to fly there.
Of course, that is just my opinion.