Setting up multiple libraries keeps things organized and makes it easier to access the specific ship(s) I want to read after seeing a video or post with the specific ship(s). If a book has more than one ship it is either put into the library of the ship I like most in that book or it is in the libraries of all the ships. Makes life easier rather than searching for a book in my private library that has all of these many books. If it doesn't make sense well neither do I. Enjoy.