How about doing away with the "Zero Advantage"
As far as I know UV doesn´t have a Zero advantage besides pilot experience.
It was a relatively short superiority enjoyed by the Zero as the Wildcat eventually (when used properly) proved it's equal and then came the improved planes which made the Zero a flying coffin.
Taking pilot experience out of the equation a Wildcat is not equal to a Zero. The Zero is the superior fighter. The US developed the Thatch Weave, and this is a defensive maneuver for this very reason. Their losses would have been much, much higher had they went traditional dogfighting against Zeros.
Perhaps the Allied fighters need a system that incorporates a defensive bonus when going against superior Japanese fighters. This defensive bonus should not give them an offensive bonus to shoot down Zeros, but simply be defensive in nature.