One is the account the campaign manager is using and another is the alt. One of the campaign rules is to not use alt to apply but if the campaign manager use his alt to apply but just one alt, that will not be considered as alt. Or you mean they use more than one alts to apply?
Even if it is just one alt account, that’s still considered cheating. And even the rule they set, which prohibits the use of alt accounts, is often violated by dishonest bounty managers. If you look at the reputation board here on the forum, you will see many threads where I have exposed these kinds of managers who manipulate spreadsheets, allocate large stakes to their alt accounts, or even take the entire campaign budget and pocket it without distributing rewards to participants.
In my opinion, bounties are dead now. Only a very few are worth paying attention to, and the rest are just garbage run by unknown new managers.