i think they created bot accounts and do all this using twitter API. if you remember there were services for fake twitter followers, later blocked by twitter few months ago.
Could be. Twitter API, however, wouldn't allow reposting in a way that is required by the bounty campaigns. Even today, 95% of the twitter accounts created for bounty purposes have fake followers. Those services just get smarter as twitter's account audit systems.
A newbie account is barely a clue. From the looks of it, it seems like a throwaway created for that airdrop.
By all means, farming a bounty with more than 200 accounts is a complicated job. OP, good luck on your quest.