Seems like all single handed weapons are always Dual Wielded in JC3.
I never dual wielded weapons in JC2 (I tried it with a few, but didn't stick to it), so to me this seems a bit needless. Sure, Rico is badass enough to dual wield anything he can use single handedly, but suppose I'm holding a steering wheel, or handle bar, or bottle of Pepsi in the other hand?
Also, dual wielded pistols were actually my most commonly used weapons in Saints Row 3.