Agree that they are separate institutions (EMU, CMU, WMU, other?), but with that particular collection, what is the "main university" you are referring to? Or did you mean system? I think they're separate but perhaps are part of a 'system' that may be governed centrally with certain administrative or political functions. That system, if it exists between the multiple directional Michigans and perhaps even Michigan Tech, Wayne State, Ferris State (and any others?), but may not include MSU and UM. My guess is that these latter two are not part of some overarching system for the overall state.