Galaxies in that fight against the Anti Spiral acted nothing like galaxies and were about as large as the Earth was.
Not from what I saw. I do remember the Anti-Spiral opening up a portal to view the Earth but I don't recall it be directly next to the galaxies to scale for size.
Plus, Super Galaxy Gurren Lagann was already dwarfing planets, and planets were smaller in size by comparison to it when the Anti-Spiral ships started throwing them at SGGL IIRC. TTGL is much larger than SGGL.
Said portal was appearing to be quite a distance from Earth to begin with:
The fact the rocky planet the Anti Spirals had sporting on their head suggests their scale isn't anywhere close to spanning galaxies.
It wasn't that much larger given that last final attack, maybe 2-4 times larger at best.