You are giving the army sniper the unfair advantage of having the long range weapon. In a real fight the rest would kick his a$$, and then the SEAL would do push ups on top of the bodies of the others.
An army sniper in position to make the shot could take out anybody. Face-to-face he'd be practically helpless. One-on-one I'd have to say either the SEAL or the Green Beret. They are both special forces and receive advanced combat training.