Okay let's not be ridiculous about this.
The Underbelly worked specifically because the seals Aizen was wearing created gaps in his reiatsu that Nanana was able to shoot through and knock him out. It's much more akin to the True Shikai Ichigo vs Askin fiasco than it is Aizen being that weak.
Liltotto is also only stated to be one of the stronger Fem-Nazis, yes she probably is still on the higher end of Mid-Nazis but that's about it. She's not beating versions of Aizen that can beat the Exiles in any state, let alone Dangai Ichigo.
I'm more explaining those very factors get rid of the Transcendence notion as well as the fact that we can't just say that Dangai Ichigo and Monster Aizen would matter in this arc alone because "Their Reiatsu cannot be sensed" than anything else of that nature.
Maybe I did push it but I don't fully agree since none of the Exiles was legit going in outside of maybe Yourichi(And Yourichi tends to get some weird shit down like she can hurt herself on Yammy's Hierro which never made any sense unless we go with her still being massively rusty till the Post Timeskip)
Well I would assume he did actually watch the fight or he wouldn't be able to make the comparison. He did show up immediately as the seal was kicking in after all.
I'm more talking about the dude saying Urahara comparing Kurohitsugi the entire time which meant Urahara would have been surveying it for far too long vs. more seeing the final bits which would make sense.
Now I do actually go with the idea of Bankai Yamamoto being stronger than SOME of the Hougyoku forms at least. Monster Aizen and Dangai Ichigo might be pushing it just a little bit.
Just saying you might be going a bit too far in the other direction here.
Honestly, I doubt Bankai Yamamoto would have any issue with Monster Aizen or Dangai Ichigo but that's more of Aizen and Ichigo really not coming off all that impressive in the grand scheme to be frank(Gin's Bankai can still injure the form before Butterflaizen is the easiest point even if "Aizen allowed it" which is bumpkiss).
But yeah in terms of pure visuals, nothing overtakes Gremmy, which would still be a stupid argument but it's not one that helps pre-skip supporters.
I'll calm down, I'm just tired of people using those stupid feats for "maximum power" when it's the same shit you usually see in most Shonen or most media.