I had the same problem, but worked around it. I decided to leave all the authors in the author category, but under author sort I put Anthology. Then used quick preferences plugin to change the files to put the books under the author sort instead the author. This puts them all in one place is something searchable without the file names getting to long with so many authors.
This was a good work around for cookbooks as well.
Just an idea
Auntykatkat