How to Complete Wanted: Tonberrion
The objective is to defeat all foes within four rounds. The enemies are three Tonberries and a Tonberry King. They can all inflict the Stalk status on a unit, and then they can later use Knife or Karma on the stalked unit, which is pretty much guaranteed to instantly kill him or her. Therefore, you should attempt to keep your distance from the enemies and use ranged attacks on them.
If you want to avoid breaking the law against Copycat, try not to have more than one unit with the same job, and avoid using standard Attacks. If you use a job's unique abilities, a unit's action is less likely to be the same as the one that the previous unit used.