I only know that another thread on here discusses a glitch when a large shared library has multiple people adding records to additional groups, it appears to result in duplications not experienced by the “owner” of the library. That would need to be explored with the development team and tested I guess before I moved an entire organization to sharing the cloud library or shared groups in a big library. But one user can only sync one desktop library.
We use one big library. I do have it synced to the web, but everyone who uses my library uses it in the way I described, locally.