It still makes no sense. No matter how good any shinigami is, it still violates what Aizen himself said and why he created the arrancars.

That is the 4 basic fighting style, Deamon Magic (Kido), martial arts (bare fists), sword style and I can't remember the last one. No matter how one masters all 4 of the fighting ways, there's always a limit. The only way to pass the limit is to release the border between hollow and shinigami. Eliminating the suppressing  energy which limits one's fighting ability.

Arrancars and Viazards are supposed to be released of those limits while captain class Shinigami still bound to those limits.

Maybe he need to negotiate with his hollow again? Like this the author would gain another few chapters of filler.

Attack from behind eventhough might be considered as cowardly, but it is one of the best tactics.

I'll take that as sarcasm since Kenpachi left her in SS He's skinny now maybe he lost some weight running here and there, slashing around

She's just too weak imo. They should make her stronger. I'm so thankful for her receiving her powers back.

BTW, I noticed the strongest captains' (Kyoraku and Ukitake) zanpakuto all don't rely on insane strength. Rather, they have unique abilities.

And on the contrary, the weaker shinigamis (Renji, Rukia, Matsumoto etc.) have zanpakuto that has pure offensive powers.

Hmmmmm. Worth pondering.