OK. Hope this clarifies.
If the prayer leader is a VOLUNTEER, non-clergy, that is he is not living off of the mosque funds, then he can be the joe-six-pack.
However if the prayer leader is a “professional”, that is living off of mosque funds (either partly or for all his expenses) then he gotta be a specialized person. And we cannot say about this person — sub chalta hai ji. We have to be serious about this issue. religion is no joke.