Would having both (and more) relationships be confusing?
I think Author-Work, Author-Edition, Publisher-Edition and perhaps even Publisher-Work could be necessary to describe all the possible cases I can think of, or read about.
This FAQ from the Author’s Alliance has some helpful comments, from this question onwards:
Do authors always own copyrights in the works they have created?
No. The constitutional and congressional bestowal of rights on authors does not mean that all authors own copyrights to the works they have created. In fact, they often do not. Under some circumstances, the individual people one might refer to as the “authors” of copyrightable works are not considered authors as a legal matter at all. Instead, under the “work made for hire” doctrine, their employers (or sometimes a commissioning party outside of the employment context) are deemed to be the authors and therefore the initial copyright owners.
[…]
Where the work made for hire doctrine does not apply, authors may start out as copyright owners but give or sell their copyrights to others. Indeed, the practice of authors transferring their copyrights to publishers has been commonplace since the Statute of Anne first granted copyrights to authors. Authors might sell their copyrights to publishers for a lump sum, or for royalties based on how many books the publisher sells, or a combination of the two. In today’s academic publishing environment, for example, authors frequently transfer their copyrights to journal publishers for free—realizing their rewards in terms of publication in a prestigious outlet as opposed to direct monetary gain. What publishers get in exchange is the ability to control when and how many copies are published, at what prices those copies are offered in the market, under what circumstances new editions are produced, and more.
And also this page about US copyright law: Copyright Ownership: Who Owns What? - Copyright Overview by Rich Stim - Stanford Copyright and Fair Use Center