I said a long time ago if I were to cull the number of characters, I'd start with at least a chunk of the vizard. Obviously Shinji and Hiyori have plot importance, little as that was realized, and Lisa at least has the connection to Shunsui and Nanao, and Kensei is a badass while Hachi is a plot device and thus necessary. Love, Rose, and of course Mashiro however can be removed with little affect to the plot.
It'd actually be a rather easy fix too, all that would have to happen is a number of them 'die' during either the point when Kensei turned into a hollow, when Aizen cut them down, or thanks to their own instability during the hollowification process. Not everyone should survive that unscathed, to drive the wound a bit deeper.
Presuming I had a bit more control earlier down the line, I'd also probably reduce the overall division number, potentially restructuring the entire Gotei if need be to cull a few of the extraneous vice captains at least. Maybe have it run by about 4 or 5 division heads (Seniors and Aizen probably) with subdivisions under one of the head's jurisdictions where the other captains would congregate as needed as 'Subdivision heads' or whatever military title would be more appropriate.
Yamamoto obviously heads most of the important stuff like the ninja squad and the Mayuri's science department. Naturally this would mean if we want to remove everything evil in SS that remains after Aizen defects, we just need to destroy this entire group. :snigger:
Ukitake obviously would handle a lot of administrative stuff so that'd tie the 9th into him with their newspapers stuff likely nabbing the 7th also since Komamura and Tousen are buddies. 4th is the healing squad so other than the Kido division they probably wouldn't need subdivisions (or I suppose her and Kido could be a subdivision of one of the others), and Kyoraku could take those misfits under his Jurisdiction like Byakuya and Kenpachi, probably making him a more overall combat oriented division. Aizen obviously has Gin under his thumb, but also presuming Aizen heads investigations that'd likely also put the 10th under his care, which could have all kinds of fun implications after his betrayal with Hitsugaya being the only commander left in his whole division. The paperwork increase would be massive.
h43r:
As I said before I'd likely remove the Shiba storyline entirely since that went nowhere, or at the very least jut cut Ganju since he was rather extraneous no matter how you slice it.
Now the Espada are quite a bit harder to restructure since the numbering mechanics is key there, but I'd want to at least double the number of higher level ones so we have something to work with, that or at least make the Privaron concept more relevant so they're actually (Much like my Gotei structure) the direct servants of the Espada, rather than the much weaker fraccion. Would help to scale up the encounters more properly so the majority of them (save the Halibabes obviously) aren't worthless decoration next to their Espada commander half the time.
Naturally, given the lack of Privaron, this would mean scaling up a lot of the existing fraccion in powerlevel so they are more formidable. Maybe also have it so the privaron also command a squad of fraccion as needed. So for say Grimmjaw's group he'd likely have one or two Privaron, and the rest would be fraccion also under his command, but in a pinch would take orders from the privaron. Obviously Shawlong, being essentially the subcommander already would be one, but considering the amount of power Eldorad showed off he'd likely be the other, since he was probably the most impressive of the bunch. Almost more impressive than the Espada in a lot of cases. :huh:
Not sure what I'd do with Barragon's lot though since basically no one stood out (Save Yumichika's Fabulous foe, but even then not as SUBHEAD material). Maybe just the one Soifon fought? Plus maybe that guy Hisagi had a fight with since the mask thing was interesting. I suppose Ikkaku's whale guy might be a possible too. Oh, that Hawk guy who had a second form was pretty neat as well. :hmm:
I'd also make sure to properly integrate beasts like that sand guy and Superchunky into the group more directly so it's less of a complete waste of space for that thing to show up in the middle of the arc.