I would have an army of modern silent assassains, all would be wearing the sam fisher armour which is the Objective Force Warrior, so you wouldn't hear them coming, all armed with a silent M9 pistol a silenced MP5 with an extended magazine and a combat knife, the team would also include a demo man and a medic, they would be tasked with doing high priority missions on the low low so no one would no who they are where they were or what they would be doing even after it had happened. Call them what you want but it better be damn badass