exactly the discipline of war don't have this problem because there main function is there weapon and role, plus the discipline of the hand and land are all different so they don't suffer from the identity crisis either. The only ones that really have a identity problem is the magic classes. Now I know that you can mix and match anything which will bring the same problems, but that why I put my suggestion of the limitation system. As for Blue mage I believe its very possible to also add them very easily since monsters already have the animation for monster skills. maybe the only thing needed would be more monster skills to add more variety. Anyways very soon I will add a Blue mage type job to the suggestion. (still looking for a good name to fit the current naming scheme. let me know which one you guys think would fit best.)
-Mimic (Cairderes name for the class)
-Illusionist
-magician
-Animator