That's definitely where the ethical line is, and makes total sense. Nearly all professional writing you read (books, magazines, etc.) has gone through a similar process between the writer & editor. It's totally expected, but nobody pretends it's not still the author's work. There are thousands of ways to write the same essay, hundreds of which are "good" (acceptable by the editor/consultant). But a ghostwriter only writes it one of those hundred ways, which is almost certainly not the one you would have picked.
It also comes down to a quest of fairness. My public school counselor happily read over a couple essay drafts. They never would have written one for me (that would have required hiring a ghostwriter, which I definitely couldn't afford).
I hope you can see the difference.
It is more like this: the consultant make the interview, just like the ghost writer, to know what to write about. Then the consultant tells the applicant to write about "this, this and that. In this way, and don't forget to mention this and this".
Then the aplicant write it. The consultant read it all and says: "this sentence is out of place, you don't need this one, you must include another one on this paragraph". And this go on and on, 5, 6 or even 10 times. Keep in mind that these are essays of one or two pages. The end result has nothing to do with any original writing from the applicant. It is more like a dictation.