Given that the Barrelsmith Set (which is the only other two weapon set) enables dual wielding of guns, it only makes sense that Nex and Ortus should enable dual wielding of melee weapons.
I realize that the Barrelsmith Set is partly a legacy of pre-expansion Grim Dawn when there was no class that enabled ranged dual wielding. However, if that set, which has far better item support in general, doesn’t require a class or item to dual wield, I don’t understand why Nex and Ortus should. This would not only make Nex and Ortus more useful (because let’s be honest, how many Nex and Ortus builds do you see? The only ones I’ve run across are ones that exist solely to try and make the set work, and they generally aren’t particularly successful) but it would make the overall dual wield item situation more equitable (even if there are many more items in general to allow ranged dual wielding, most of them aren’t relevant at end game.)