Well, I also wouldnt say its downright impossible for a campaign manager to secretly run an alt account pretending to be a genuine participant. But it does seem pretty darn unlikely if you ask me. Setting up and maintaining something like that would be a ton of extra work for them. .
I agree; it's too much work. They are managing campaigns, looking for new clients, and checking their participants.
Having four to five campaigns is too much; they cannot keep up with their numbers, following, and creating discussions.
A campaign manager can do that if he is only managing 1 or 2 campaigns, but more than 4, it will consume time and effort; they also have personal lives.