Thread:Njalm2/@comment-136273-20151110195722/@comment-3403804-20151110232254

My own view on the matter is that there's a reverse curve between Jack and Specialists. True Specialists are often weaker than Jacks until they reach a certain point, for instance, while Blank's Naomi is technically a Kido Specialist, she lacks the means to use it efficiently and she's therefore by and large significantly weaker than most other Lieutenants in combat.

However, once your character reaches a very high point, such as above Captain-level, Specialists tend to be much more powerful than most Jacks, and Kido Specialists in particular are often ridicolously powerful.

The reason I believe that Specialists are uncommon within the Bleachverse is largely because of this, when they start their careers as Shinigami, they're probably strongly encouraged to remain balanced and flexible, and learn as much of the Zankensoki as they can. As they advance in the ranks, I guess they just stuck to that, hence why most of the Shinigami presented in canon are well-versed in a lot of different fields. Hachigen and Ichigo are largely the only specialists seen in Canon, after all, and Ichigo is specialized out of neccessity and not by choice.