The very point of him being able to learn stuff from the enemy (and there's a bunch of stuff you can learn without going out of your way) is to make him more versatile. Do you need someone who can use Armor Break without not being able to move again? Pull an Auron. Do you like going pew pew with lazerbombs? Make a second Black Mage. More people can have fun with Kimahri if they would but a little bit of thought into what they want from a character that is virtually built from scratch. That also gives you 6 primary options, and any number of intermediate positions.
The problem comes with Kimahri being moldable into any function that you desire.
