So here is my idea:
One team has to escort a Covenant Scarab (or USMC Elephant as a variant) across the map. The other team must destroy the Scarab (or Elephant) before it reaches the other side of the map. Players can use guns on the Scarab / Elephant but cannot drive the vehicle. To start the game the convoy gets several AI vehicles to travel with the Scarab / Elephant.
Edit: I suppose we would need new maps for this game mode to work.
