Oh of course. Shotguns are also secondaries, so you can carry two shotguns (or dual G18's are also broken). That means you can carry an Assault Rifle/LMG, a Javelin Launcher, two shotguns, a special nade, and a grenade while sprinting top speed.
Still not enough hilarity? I've successfully won far too many games using ONLY a knife. Lightweight, Marathon pro, Commando pro, some stuns, and a pistol with a tactical knife. You run riduclously fast, have a fast knife, and can stab someone from a few meters away. Just take wide flanks, get like 5 people in a group. See someone up ahead that is facing your general direction? Stun him, circle wide and stab him in the kidney.