To answer your question about the reason for the differences in the types of garotos who frequent the two main saunas in Rio, 117 and 202:
it’s a combination of club management and club reputation. 117 has been for years and is still currently known as the sauna most likely to have garotos that are more muscular (“mais forte”), while 202 over the last decade, due to its Junior takeover, has become more of the sauna for twinkier, slimmer garotos (“magrinhos”, “novinhos”). Although these descriptions aren’t mutually exclusive, and you can find exceptions at both places, the clients who regularly attend either of these places are generally attracted to the types described that regularly go to those saunas. Regarding the “mulatto” description, since almost every Brazilian is mixed with something, it’s hard to understand what you were getting at. I think the percentages of brown, black, white or indigenous looking garotos is about the same at both saunas. The observedly marked differences between the garotos at the two clubs seem to be more in body builds (skewing skinnier at 202 than at 117) and in ages (skewing younger at 202 than at 117).
10 or so years ago at 202, under different management, 202 had a different crowd of garotos, and was more known for more muscular guys. Not the case at all now.