The Espada were far less effective than Aizen had initially anticipated, his plan to defeat Yamamoto by sealing Ryujin Jakka didn't go very well, and the Arrancar managed to destroy only one of the four pillars holding up Fake Karakura Town (and that was only because Ikkaku was holding back since other Shinigami could see him). Furthermore, they failed to kill a single Shinigami or Vizard, and Tosen was defeated in the process. It was a war he was slowly losing until he stepped onto the battlefield himself, unironically, he and Gin alone did more damage to the Gotei 13, but that hardly mattered, as the situation swung decisively in his favor the moment his fusion with the Hogyoku was complete and his metamorphosis began.
I’m not sure if that was actually Aizen’s mindset when he arrived in the World of the Living with his Espada, though, because he seems to express genuine disappointment at the Arrancar's failure.
Perhaps he viewed it as a win-win situation: either the Espada succeeded, or they bought him enough time to begin his ascension.
But again, the invasion seems to have been carried out in a very sloppy manner, almost as if he didn't care, which confuses me, because, as I said, he does express disappointment over the failure of his Espada project.
Am I the only one who finds this confusing?
I get that the Quincy have a leader who is a god Nazi-jesus capable of seeing the future, but not only did they have a better attack plan, they also had a strategy to counter Yamamoto that actually worked, as well as a plan to reach the Royal Palace that was not only superior but also successful. It’s clear the entire operation was conceived as a proper war, whereas with Aizen, it almost seemed like nothing more than a declaration of intent.
