Well. Her weapon is a moogle that turns into a bow...that can convert to a sword. Also you can throw the moogle outside combat and he'll fetch distant swag for you.

I SUPPOSE AT LEAST THEY DON'T MAGICALLY CHANGE SHAPE YEAH. Although presumably Noel's interlocking his swords or something weird like that.

Figure it might be compensation for the crushing despair that's usually visited upon them at least a few times over. That or it's a case of, "this looks cool let's do this thing." But everyone needs nonsense-weapons.