I worry about a title "Only" matching. I have 2 or 3 'duplicate titles' that Are Not (different authors-different books.
Then there is the case of different 'Editions' of a book, when it changes publisher and get a
edit job
I prefer an 'always ask' option (toss, make new entry, Merge), issues that could be held in a queue so as to not interrupt the rest of the batch and presented to the user near the end (like the current problem status, only allow browsing the library before marking what to do.