Me and my buddy have 1 Flag on Sword Base down to a science. It literally only takes like 30 seconds for us to capture the flag each round provided we have at least 1 other decent teammate.
Here is how you do it:
On offense, someone uses the Sprint loadout and rushes to the edge, jumps over and lands at the entrance to the flag. He immediately tosses both grenades towards the far right corner where the other team is coming from, then grabs the flag and runs out the way he came, turning left to head towards the grav lift. One other person can help by jumping down and throwing more grenades/covering the flag guy.
The other 2 team members rush the sniper and then cover the flag guy as he runs for the grav lift. One of these people should use a Jetpack loadout. As the flag guy takes the grav lift heading towards the flag capture point, he should toss the flag once he reaches the highest point. This will get the flag literally 2 steps from the capture point. Then the Jetpack person who was helping cover the flag guy and protect the sniper should take the grav lift, fly up to that level, grab the flag and score.
On defense the key is the rush the center and guard grav lift rather than actually rush the flag. Rush outside to the grav lift and toss grenades/shoot your weapons towards your flag spawn and they will never be able to reach the goal. They may try to take it the long way, but it is easy to stop them those ways and return the flag.







