I know AI is very challenging, but I'll ask anyway. Please try to make the AI a bit human.
1. Survival instinct. Not even the Japanese fought every battle to the death every time. If a plane gets shot up, make escape a top priority.
2. Make flying and shooting skill relative to pilot skill. Skilled pilots should make fewer mistakes and have more maneuvers up their sleeve. Newbie pilots should have a more limited decision tree and be more prone to doing stupid things like turn fighting in a Wildcat or flying straight and level. Skilled pilots should also have better SA. Make it possible to bounce the AI.
3. Make the AI stop fighting and go home. Pilots simply did not chase everything they saw all the way back to base. Put the AI through some simple decision making before it decides to engage. What are the odds? What is the situation in terms of relative energy? What is the combat situation - i.e. is it necessary to risk all because your carrier is underneath you or is the situation more mundane and engaging at unfavorable odds is a bad idea. Allow the AI to decide on a hit and run approach instead of engaging to the death. Once the AI is set on a course, let them stick to it as much as possible.
This does not have to be some sort of massive AI experiment to create the perfect AI combat sim pilot (although if you want to do that then go for it). I am talking about add something on the order of: if (condition) accounting for pilot skill do this with a bit of randomization thrown in. Enough such that combating the AI is a varied experience.
Thanks for listening.