The SMG was designed to encourage the player to hunt for better pickups, and that drove map flow.

Some series of dual wielding combos work quite well to counter BR and other power weapons; first I should not that only the SMG has recoil/muzzle drift in the dual wield category.

Tripple wielded needlers are pretty crazy, to do this pick up one needler switch to your other weapon, which aught to be a dual wieldable one, pick up another needler in your left hand and then pick up a third needler in your right hand and now you have an OP pink storm with stupid ammo dumps where your skill should be.

SMG/either plasma rifle; plasma strips shields real fast and human weapons hurt the unshielded spartan more than plasma, using both will murder in a close enough range this technique can be replicated in almost any combination of SMG/pistol with plasma weapon.

Don't wield only one needler, it's a waste of your time and why they removed dual wielding these things in H3

Dual wielding fully auto weapons with at least one SMG will allow you to take care of sword and shotgun players if you can creat some distance; it's a skill to anticipate these players and make such distance but you can learn it easy.

If you don't mind early onset arthritis and you have fast fingers dual wielding pistols can actually drop a BR player quick in closer ranges but still further than other weapons can engage a BR, you can also reliable suppress and approach a sniper with these things so long as you take a serpentine approach. Of course it's super easy to just noob combo kids with a plasma pistol charge shot and a head shot from a pistol.

Learning weapon placement for dual wields offers a distinct advantage in H2 even in BR slayer because taking out a shotgunner or a sword guy is easier in tight quarters with more specialized close range equipment and mastery of melee timing.