Agree. If we assume a 5 seed, those 3 are almost certainly on 12 line. So there's 75% chance, realistically.
My best-guess for the other 12 is probably one of these (in order of likelihood):
(1) A-10 auto-bid
(2) UAB (if it wins C-USA auto-bid)
(3) Late bid steal as AQ (Vandy/Ohio State) or Vandy getting at-large*
One First Four could be on 12 line, but more likely both are locked into 11 line.
* Still thinking it's win AQ or out for Vandy, I don't think def A&M is enough to climb into it. But I've been wrong before!