I'd say adding a way to disarm your opponent, and your opponent being able to disarm you, could be a good mechanic. Disarming your opponent could work by cutting their HANDS or ARMS in a specific way, meaning "badly" cutting them or hurting their hands.
Also add a mechanic that when a player cannot hold their weapon properly (or if they choose to drop it), they can press a specific button (keybind editable) to drop their weapon and fight with their fists, and when they hit the opponents head, hard enough of for a specific amount, that player that has been hit with the fist, if they have a weapon, they drop it by "concussion", if they don't have a weapon, they fall to the ground or stumble/struggle to stay on his feet. On some specific weapons, that have handles or hard surfaces, make an attack or make it so that if they hit someone with it, they get a concussion, so they either drop their weapon or stumble.
Since they'll drop their weapons, make it so they can also pick them up, pressing a button ("attack left" and "attack right" buttons at the same time near the weapon) for example.