Look, it's really very simple.
They make StingRays and Sterlings.
The Sterling is a 4 string version of the 5 string StingRay.
They also made a 5 string Sterling, so a 5 string version of the 4 string version of the 5 string StingRay.
Their budget line is called Sterling by MusicMan, which have nothing to do with the Sterling. Unless it's a Sterling by Sterling by MusicMan.
Sterling by MusicMan also make StingRays, so it's a StingRay by Sterling by MusicMan.
They also make a Ray34 (4 string, unless it's a 5 string) and a Ray35 (5 string unless it's a 4 string)
They used to make the S.U.B. but everyone liked them so they stopped, then they made the SUB which is a different thing to the S.U.B. They also make the bongo, which isn't a bongo, it's a Bass and looks like HR Giger and Hieronymus Bosch had a bet as to who could make the ugliest thing and they both won.
Hope that clears things up!