Add AI GVs. Lot's of them. Spawn them and let them fight in the middle between fields. When something dies, it spawns back in a bit further home, moving the front.
That provides targets to planes. Targets for player controlled GVs.
Distraction for planes, the probability to hit a player is reduced.
And it creates something that feels like an actual fight, not a binary drop-troops-the-right second battle.
If a single GV hides or not, can be found or not, no longer matters. Hiding is still possible, but not effective (can't follow the moving fight while hiding).