I think we can all agree that Mike Tyson would be MORE dangerous with a knife than not. Even if he’s never experienced using one before the moment he decided to aim it your way. He’s still going to be moving well, blocking well and using that empty hand of his.
Or that Musashi historically could out-swordfight you with an oar from his boat.
To that effect, I’d recommend moving away from ‘martial arts weapons’ vs ‘non-martial arts weapons’ as they are now. I’ll explain.
Bare Hands, fist-weapons and those that define a style (Fencing, Silat, Niten Ichi-Ryu) have access to all of the techniques. (With the caveat weapon based martial arts should care much, much less about what weapon you’re using. A crowbar isn’t a bokken, but you wouldn’t be clueless in how to use it like one.)
Anything you can wield in one hand still lets you mix in arm / leg blocks, specific set-ups and dodges, movement related abilities, clinches, trips, throws, kicks, etc. Anything you could imagine a practitioner pulling off with one arm free and the other less so. Maybe lower the weight of them going off, and over-ride certain attack-techniques with just those inherent to the held weapon.
Anything that’s taking up BOTH your hands is much more limiting. Movement options, dodges and certain fake outs / set ups might still work. At this point you’re pretty much brawling if you don’t know your way around what you’re swinging at someone.