I think if one person enrolls many alts in a campaign who post a bunch of garbage, I think it would be more accurate to say the campaign manager is scamming the company ultimately paying for the advertising, more than the person who enrolls the alts because it is the campaign manager not doing what they are being paid to do -- screen and vet campaign participants.
I have a completely different opinion about it.
If the rule is one account one person, and one good poster can't join the account because another with he same quality of posting is stealing spots, the abuser deserves a red tag (99% of cases).