To many vehicules in the same time in conquest maps.
Should make avaliable only 1 air and 1 ground vehicule at the time for each team. When a vehicule is destroyed, another vehicule of that class (gound or air) spawn (randomly between all avalialbes vehicules in the game).
Would help reduce opness of vehicules beause now half of the team has to be engineer if you want to even have a slight chance of wining against vehicules.