1. Maintain strict formation. Not just simply move at the same time but move in set formation.
2. When someone quits have their account go to AI. Rage quits are annoying.
3. Have a game version that allows for military planning before engagement. Set specific time for doing this. Maybe four minutes where entire battlefield is on camouflage and hide units.
4. Have airplanes return on on same path selected to engage target, not directly to airport and over AA.