I played the original FF3 a while back, and my monk was awesome. His defense was lacking, but generally speaking, I could always count on him to do more damage than my fighter/knight on any given round.
Now, on the DS version, they've ruined the monk. He's so weak. At this point (very early on), my "Warrior" does about 70-80 damage against the average enemy. My "Monk" does about 6-18 damage against the same enemy.
I hope he'll get better when I make him into a Master, or Karateka or whatever they're gonna call it.