Flexor the Mighty!
18/100 Strength!
I wouldn't allow it, unless they had a reaction.
Sounds like your real problem is with 5e Fighters and feats in general. Yes, they are powerful, but doing this isn't broken. As mentioned above, whose to say a monster wouldn't eat the fighter's sword, or it get kicked into a fireplace, or stolen by a wiry goblin that happened to be watching the combat waiting for something valuable and the opportunity to grab it.
I don't see knowing the parameters of the class well as a problem. I like the fighter and I don't think it is overpowered as a class, I'm just not going to pretend like giving the functions of a feat for free is fair and balanced. Most monsters in the MM won't be able to hit you without a crit with that set up, so it won't matter.
Why couldn't it it's an Arcane Focus?So a wizard with a staff couldn't cast a spell?
Why couldn't it it's an Arcane Focus?
So a wizard with a staff couldn't cast a spell?
I allow a focus to be used for somatic and not just material components. It's a house rule but the only thing that makes sense IMO, sorcerers need to be able to wave their wands and make magic happen.
A spellcaster must have a hand free to access components or to hold a spellcasting focus but it can be the same hand that perform somatic components.If it has a somatic component it requires a free hand.