Second weapon glamour!

[weebtext]

The only way I can see this not looking weird is with a MCH using a dagger, and only because the QSB-91 exists.

[Iscah]

At a practical level, weapon types are strongly tied to job animations before you even consider theoretical "identity". Replacing one with another will result in all sorts of strange animation clipping and strange ways of holding weapon pieces.

I'm not just speculating on this – for a while at least, there was a glitch happening where (if I remember correctly) if you'd saved a weapon to your "try on" menu and then tried on additional gear pieces after swapping to another job, the character would sometimes go into the current job's stance with the saved mismatching weapon.

I've got screenshots saved of odd things like holding RDM's rapier as a bow and arrow – rapier as the arrow, focus gem floating over the bow hand IIRC – and a staff held in RDM's battle stance sticking straight into the character's stomach. I'm sure actual battle animations would get even weirder.