Yes, I get that. I'm just wondering how any of these units are supposed to gain fans if they are not consistently promoting.
The only way I can see that happening is if Triple S as a whole somehow blows up or one of the members becomes an IT girl and gains a crazy fanbase. Other than that, I can't see how a rotating group with no real fixed subunits will be able to gain a solid fanbase.
It's a harder sell in Korea because people get too invested in the members, but these types of groups have been popular in Japan for ages. Morning Musume for instances has several random subunits that only releases one or two songs. They've been going strong for 25 years now.