Scaling relied on Aizen being superior to Espada and not 100% hollow Ichigo. 100% hollow Ichigo never fought anyone
So he kinda doesn't scale to anyone, You can say Aizen stronger than him as a ''Transcendent being'' but i cant find reasons for base Aizen.
As I said this above, Ulquiorra said that to make ichigo feels despair, context in here is:
Ichigo be like, oh you are the strongest espada, if i beat you then I'm stronger than all espada, Ulquiorra then show his numbers to shatter his spirits
He also do this with his SE, Ulquiorra in his Res1...
That was their main defensive capabilities, you can said the same for Sonido, they can move without Sonido but their fastest movement will utilized Sonido.
Zommari is the fastest and Nnoitra is the heardest to break if you do by Databook and Manga.