
So, as you probably know, near the top of the base are several flags related to sight: Cloaking, Stealth, Seer, etc. Grab CL, so that you won't be destroyed by all that laser sniping (for those who aren't in the know, you can't use a laser to kill a tank with cloaking. the shots go right through). You'll need to have 5 people up there (all cloaked), including yourself, to execute this plan:
Still on the top of the base. Two tanks go to each side of the top part of the base. The other tank goes in the middle. But if you have a lot of tanks on the other team firing through the middle, that tank should take cover behind one of the pyramids up top.
On signal, the four tanks who were on the side jump off to the ground and advance towards the opponents base. They are split into two "squads" made of two tanks; if you're one of these tanks, you're squadmate is the person you jumped off with. Anyway, as they make their way towards the other team's base, they take cover for each other and watch the other squad on radar. When they rech the destination, both squads charge inside and invade the base, defeating all other enemy tanks inside.
Once they make it there, it's the other guy's turn. You know, the tank who was waiting in the middle or taking cover. He goes out and heads straight for the enemy base, grabs their flag (the other guys who invaded the base should still be holding the enemy tanks off), and heads straight back to his base to cap.
A variation could also be used that uses 6 players: the one tank who was going to cap instead becomes of a part of his own squad. The other squad member covers him.