I got tired of being swamped by enemies on the last USA campaign mission, so I tried something. I hid my con-yard and proceeded to level up my Abrams that are provided. I ended up never using my con-yard and beat the mission in 13min with just the Abrams. Since you don't deploy the con-yard the enemy never triggers the endless annoying hordes of doom.
Obviously this is an exploit, but it's well deserved because that mission sucks and needs to be rebalanced. WAY too many enemy attacks WAY too often.