This is an awesome idea and if you ever get it off the ground, I got just the character to fill the role of being the muscle
Also, just to pitch an idea here, you could have two leaders of the group;
A strategic leader(the manager)handling all the contracts and sorting out what guys/resources/ect that's to be used in said job, and also handling the "birdseye" side of the missions.
And a tactical leader(the team leader) running the missions on the ground, making sure everything goes off according to plan.
You could also open up a spot for a PR-type guy, being the liaison between the client(s) and the group. Charismatic, fast-talking, reassuring and easily likeable, he would be the outward face of the group, which could also have it's uses if it ever were to get into trouble with the law.
Just a few thoughts though. ;)