I think you may have overlooked a couple important roles that the DA can play. By using heavy armor, extra health, MG w/ FG and RD you can effectively "Tank" large groups of enemies by simply drawing their fire away from your squad and at you. Many times I've waltzed down a road, or around a bunker, in plain sight firing away to get as many of "them" to start firing at me as possible. Also, ya don't mention the bi pod, which when used as an area denial tool can be just as effective as any sniper, if not more so from the psychological effect of seeing hot lead filling up a hallway. If they are focused on you, then your team has that many fewer enemies to worry about while they're doing their thing. Indeed I say that yes, a Direct Action soldier CAN be a one man army, in the sense that they can draw a lot of "aggro", and lay down enough covering fire so that the enemy has no choice but to commit forces to deal with you.