@DrWizardo Just 2 as normal. Must be the same weapon, different mods allowed.
Essentially allows for double ammo capacity and firerate, at the cost of double reload time and move a bit slower while dual wielding - as if carrying a sniper, shotgun, or LMG, because those also slow you down greatly already.
Dual alternator would be like the Spitfire with double firerate and no backup weapon.
Also a bit less hipfire accuracy, and aiming increases accuracy but is still classified as hipfire, as you can't ADS with them in dual mode.