Anyway, here is my most up to date version of Gurren Laganns cosmology & scaling.
Here at last is my up-to-date (as of writing this) masterpost of Gurren Lagann! Here I will mostly go into the scale of the cosmos itself (though with
comicvine.gamespot.com
As for where I'd rank the different version of Simon (using both classic OBD scaling and VBWs current system)...
Episode 1 Simon = Multi-cityblock level
Pre-Kamina's final stand Simon = City level
Kamina's final stand/Post Kamina's final stand = Continent level
Dai-Gurren = At least small country level (completely unscathed by Dai-Gunkai exploding)
End of pre-timeskip Simon = At least Galaxy level (LordGenome had been gathering power during his thousand year idleness and was going all out at the end)
Arc Gurren Lagann = Low multiversal (according to the commentary for the Gurren Lagann movie HD remasters, Arc Gurren Lagann's Space-Time Shattering Burst Spinning Punch hits with the force of multiple universes to send the opponent outside the universe)
Super Galaxy Gurren Lagann = At least Multiversal (trillions if not sextillions of times so), possibly higher (high 1-C scaled to the higher brane dimensions, which the Ashtanga control to manipulate probability)
Awakened Simon/Tengen Toppa Gurren Lagann/Super Tengen Toppa Gurren Lagann/EOS Simon = Megaversal (1-A scaled off Otoko Simon & Avant Simon, which has genuine reality over fiction transcendance, though I am hesitent to consider the higher dimensions as layers into R >F; mathematically the Otoko-verse has 20 dimensions, and in anycase, Tengen Toppa Gurren Lagann transcends dimsions as a whole; the Labyrinth contains different multiverses of which Otoko is just one, and is eternally branching with infinite universes being set at every possible instant; Tengen Toppa Gurren Lagann is made of every Gurren Lagann in the Multiverse that was, is or ever will be, and the pilots sustained said Super Spiral Space all throughout the final battle)
As for the oponents...
Generic Gunmen = Multi-cityblock level
Pre-timeskip Viral prior to Kamina's last stand = City level
Pre-timeskip Viral post Kamina's last stand = Small country level (survived Dai-Gunkai exploding whilst on Dai-Gunkai)
LordGenome = At least galaxy level
Ashtanga = At least multiversal (Arc Gurren Lagann was unable to even penetrate ones shield), possibly higher (high 1-C by controlling the multiple dimensions to manipulate probabilty)
The Anti-Spiral = Megaversal (more powerful than Tengen Toppa Gurren Lagann, and in the movie & manga ripped it to bloody pieces; equaled the Big Bang which created the entire Gurren Lagann Multiverse)
Now, because it's no doubt going to be brought up; what about scaling from other Trigger series? IMO it's probably best to just scale Gurren Lagann to its own cosmology (as of yet it's unclear if the Multiverse of Trigger is the Labyrinth, or if the Gurren Lagann multiverse is just one part of the Triggerverse. We do see Gurren Lagann characters cameo in PSG & KLK, which would imply that Team Dai-Gurren did merge with those versions (and KLK does show a zoom-in during the final battle of many worlds-within-worlds), but it's unknown if there are versions of the Gurren Lagann cast in all of those worlds. Even more shaky is any potential crossovers with Aim For The Top!, as apparently the rights to that was sold without Annos permission and the Triggerverse had yet to be set up back then.