Author-Function and Author Agency

I left Foucault's article with a very basic sense of what author-function meant. My understanding was that was this dehumanized extension of the physical author. I understand that its purpose is discursive, but before I can unpack what that entails, I need to back up. Where does the agency of the author-function come from? Ong actually brought this question to my attention when he mentioned offhandedly that authors are "under the insistent urging of editors and publishers" (10).

Just as Foucault asks if notes, drafts, deleted materials, and published materials all make up an author's work. I want to know if the author, editors, publishers, peer reviewers, etc all make up the author-function (not the physical people but their effect on the text). If the author-function is a "result of  a complex operation which constructs a certain rational being that we call author" (909), than couldn't the editors, publishers, peer reviewers, etc be a part of that complex operation? I feel they are because they alter the text in one way or another. Are they cancelled out of the author-function when non-published pieces like drafts and deleted passages are included in the author's work since these pieces reflect text untouched by publishers, editors, etc.?

I guess it boils down to which has more agency: original (unpublished) text from an author or forces like editors and publishers? I'm hard pressed for an answer since Foucault removed the human element from "author". Did that mean that he removed the human element from the text?

(There is a good possibility that I'm completely missing what this term means and therefore my questions make no sense...)