Correct me if I'm wrong but they're special operators and DICE are saying they're Marines, so they must be MARSOC or something.
It's only confusing because of the way DICE makes their appearel look, all mixed up and shit.
Like Pac & Irish have BDU trousers with beanies, but Dunn is wearing an AOR2 uniform (Which is Navy exclusive, I think) and according to Recker's arms, he's wearing Blackburn's Desert MARPAT fatigues with different gloves. Also, the American flag shoulder patches are confusing.
Just wasted a paragraph talking about uniforms -_-