Well... they do it kinda weird. 2 primary and 2 alternate, but from what I understand, the 2 alternates almost always end up going to UPT due to a lack of pilots, if the unit can swing it. Don't ask me the particulars though, just repeating information I was told.
To your question, one off the street and 3 enlisted, although the off-the-street guy was a primary, so there's that. I got the sense that they didn't care, because the interview was about 50/50, I think the enlisted just performed better in the interview itself, since they're so used to interacting with the pilots.