Quote Originally Posted by Martyr View Post
The size of the monsters that they fight requires it.

Think about it, man. Even if you had the best sword ever, it would be wasted on a monster in comparison to which it is the size of a toothpick.
Unfortunately, that means that the FF Warriors have to learn how to use unusually large weapons as opposed to those that would be effective on humans/medium sized creatures alone.
That's flimsy. You could also say that the huge weapons are much too bulky for fighting enemies like lizards and such. It's like killing a fly with an A-Bomb. Plus, magic can be as effective (if not more so) on the big enemies as swords and such.

The size and look of the weapons has solely to do with character design. Hell, after a trek around the sphere grid, Lulu's little dolls can do 99,999 to a Behemoth or any other normal monster...