Mostly, if the other team isn't aware of that tactic, and waiting for it. Maybe send one guy to B, so on the other team's radar, it looks like your team is going there. Because these maps are mostly small enough, that your radar can sense somebody who's almost 3/4 the way across the map. Then, when they all rush there to stop your "team" at B, the rest of the team sneaks around to A or C, depending where you started from. Then the decoy player can either double back, or take pot-shots at the enemy, from afar with a scout rifle, to keep them occupied, until you're finished capping. But this is a situation where a little communication would probably be needed. I don't see a team of randoms, who aren't communicating, pulling something like that off.