Just based on their usernames and the fact that both accounts are from 2014, I initially thought they might be alt accounts, but their posting style is different--or at least their grasp of English seems to be. But they both post a lot in Economics, too. Very weird.
There must be a private way to apply in the campaign, I also see some other users in spreadsheet but they did not apply in the thread.
Yeah, I'm wondering how they both got into the campaign without applying. As you said, they might have PM'ed the campaign manager, but that seems like a very odd way to go about it. I'm thinking they might have been invited and that they might know the manager or someone else and got in through nepotism.