Looking at the rate pro BJJers gain muscle it seems like something he could do in a few months.
Anyway I find it much more likely that every steroid-less Caio beats Rafa than Geo.
This is taking the thread way out into left field, but I think we should do everything in our power to have Caio go full Gordon Ryan - get huge, and spam our IG stories with videos of him catching crazy pumps on the cable machine while his IFBB pro girlfriend (I suppose he'd have to leave his wife) hand feeds him bananas.