So, the term you're looking for is "collective noun." The collective noun for a group of owls is a "parliament."
A quick Google search shows that there is indeed a collective noun for editors, and that word is an "erudition." An erudition of editors.
No to "haggle." At best it describes a sometimes necessary yet usually unsavory transactional practice. While there is a fair amount of negotiating involved in editing, I don't think many serious editors would care for "haggle" as their collective noun.