@Jollygood, you don't normally make a topic without already thinking someone or multiple someone's in this topic are doing what you're thinking, so I am more curious of who you think is cheating. Your question also I feel needs to be split up into 2 parts.
Do you think Bounty managers are enrolling alts or have ever?
Do you think sig campaign managers are or have ever enrolled alts?
Bounty managers are a dime a dozen and mostly unknowns and I believe it is normal in their minds to enroll their alts. Even some of the more reputable managers in that space could be guilty, but I have no proof.
I won't comment on sig campaign managers without proof as it could be considered a pretty hot topic and dramafest waiting to happen. No need to open that can of worms at this time. Could it be happening, yes. is it, I don't know. I wouldn't rule it out.
I have a hard enough time posting 25-30 posts in a week on 1 account, couldn't imagine trying to make posts on multiple accounts.