I am also more than certain that, even in such cases (which I also heard of), theymos made a thorough analysis for each such user. I have no doubts that theymos would choose a merit source based on nothing. So, most likely, each such user had a good history of meriting posts from various boards, spotting quality posts and good forum contributors. theymos is a rational person, as far as I observed, and does nothing on a rush or not by analyzing thoroughly his decision and potentially outcomes.

So I believe that those selected to be merit sources without a formal application also fully deserve their position.