I'm not gatekeeping anything lol, I don't even like Luffy.
I just don't take this as a literal powerscaling statement, that's all.
Not saying it isn't a powerscaling statement at all, there is obviously powerscaling implications here. But Roger wouldn't be treated as the pinnacle of haki and equal of WSM if he's Gaban's equal too.
But clearly they are also close in power level, and are all top tiers. So a sub tier between Roger/Rayleigh/Gaban makes sense
Its also funny to see dudes clowning on Zoro fans here, though the implication is far more damning for Luffy fans lmao