Meh, pretty much none of Sitsongpeenong's other charges have become more than mediocre. I don't think any of the fighters they've bought have improved at all.
It isn't even that Sitsongpeenong is a bad gym, but they get tons of press and everyone sings their praises, because they're well connected and have a bunch of fighters (almost all bought) who get international opportunities. Same sort of thing has happened with Fairtex and Banchamek gym.
Nothing about Sitsongpeenong's history suggests that they can produce top level talent, so there's not much reason expect improvement from guys like Thongchai, Manowan, etc.