The biggest game I've played is an 8
player one and this works pretty good there.
First, have you (person '1') and a teammate (person '2') make a mad dash for the
enemy base in a warthog, if you survive, drive around to the back door but make
a wide turn to get there, when the jeep is furthest away from the base have
whoever's not driving (2) hop out and run away from the base (there's usually a
good rock to hide behind)
(2) stays still and hides while (1) runs into the base and dies. the enemy won't
see or hear shooting so they think that you've all died)
Once (1) respawns have them take a ghost out towards the enemy base and alert
(2) to run in for the flag just before (1) arrives, so that once (2) has the
flag, there's a ghost waiting for them out back!
(1) [now out of the ghost] stays and fights to the death, distracting the enemy
while (2) runs home in the ghost for the capture.
It's not really as complicated as it seems..