User blog comment:Zwann/Vasto Lordes in the Espada, let's analyze./@comment-1590714-20091017171700

If they would've been Vasto Lordes, there would at least have been some more explanation done by Tite Kubo. If they would've been Vasto Lordes, I think Tite Kubo would've let Aizen say something like: "You should fear, for I have brought Vasto Lordes to this world."