I had a few thoughts about this today. I think most agree that we want to see gv action integrated with air combat action. It wouldn't be fun for the two kinds of combat to be happening in hermetically sealed chambers where one cannot affect the other, and it also wouldn't represent the tactical realities of WW2 combat. That said, it can be frustrating to get bombed again and again while in a gv. The rule that deaths due to aircraft does not count toward the 4 allowed was a nice gesture, but might not be enough because gv play must be meaningful: your success or failure must be somewhat equivalent to effort and skill. Attack aircraft void that equation.
Maybe someone has already suggested it, but in a scenario similar to this:
1) Provide each side with a maximum quota of ordinance, and let the CO's decide how to use it. For example, side X gets 100,000kg of ordinance for a frame, to be split among units however they see fit.
2) Remove any restrictions on who can attack what. The current rule is going to be a nightmare to regulate.
With a finite amount of ordnance, each side would have to balance how much they use to destroy stationary targets and how much they use to destroy gv's. Accomplishing the first goal would place a leash on aircraft interference with gv battles, while still allowing interaction between them. CM's could manipulate how ordnance is used through the assignment of point values to stationary target destruction vs gv's.