While I agree with much of what you wrote — basically, about editors needing the experience to have developed a solid work ethic and flow — the best editors I’ve worked with, over the years, do not want to write. They do it well enough, but they love to edit. Writers who edit, on the other hand — and I tend to be one of them — have to fight an impulse to re-write, rather than to make the writer’s original words shine.