"I don't know about editors, but some publishers certainly do."
Um, I don't really understand the clarification--editor/publisher--whatever--in this case, as bonsai magazines tend to be small operations where one person holds the job of many. But if you want to split hairs...
Here's what I do know of the larger publishing world:
As an editor and managing editor of three or four publications over the last two decades, I don't know of any publishers that actually assign or find many articles. While publishers at bonsai publications may do that, it's not really the norm. I've assigned articles to writers to produce on spec. I also find experts to writes articles for me.
Here's the bottom line for an editor, editor/publisher---Anyone with the intricate expertise shown in this article, who comes to you with a series of photos to illustrate it-- would have most editors jumping to get it. It is not a long grey mantra of theory. It is experienced, knowledgeable and illustrated...
Publishers' roles are more typically behind the scenes at the vast majority of publications I've worked for, or with, as an editor and as a freelancer. They are more associated with bringing in advertising than in procuring and assigning articles. Usually, in the larger publishing world, their presence in editorial operations is a sign that the publication is either not legitimate--as in editorial content is driven by what an advertiser wants, in big trouble financially, or layoffs are about.