User blog comment:Kartik "k2"/Comparision between regular shinigami/Hollow and Vizards/Arrancars/@comment-493809-20140918152916/@comment-10497166-20140919134935

Talking about grand fischer, wasn't orihime's brother also unmasked? He however didnt get any stronger if u ask me. SO the entire arrancar theory becomes inconsistent if u consider orihime's brother. The most acceptable explanation seems to be a fault on the writer's behalf. Also, hallibel was defeated by hitsugaya and would have died from the 1000 flower thingy if not for wonderweiss' intervention. Aizen beating her came later. Anyways i dont think there can be any single explanation that sums up everything.And as none was offered in the manga, your guess is as good as mine. Perhaps it's one of those little mistakes that you find in almost every manga.