Thanks to Evidence Explained, I just came across this take on the editor-writer relationship from Carol Fisher Saller of the University of Chicago Press:
A good author-editor relationship involves working with the writer in ways that will tell you what he really wants so you can help him achieve it. A great deal of the time, you’ll find that what the writer wants, you want, too. And if you’re skilled, the writer will discover that he wants most of the same things you do.That's from the introduction to her book, The Subversive Copy Editor (which I have not seen the rest of). But it rang a bell: the 1981 classic Getting to Yes: Negotiating Agreement Without Giving In by Roger Fisher and William L. Ury.
In any setting, creative negotiation need not be a zero-sum game or compromise that dissatisfies both sides. It involves listening, asking questions, and inventing alternatives that speak to both sides' interests (as opposed to stated opening positions). But I had never thought of editing this way.