I'd be okay with Marty, and that would strike me as a Ralph move.
However, keep an eye on either A) Retaining April once he takes over as HC or B) Jack Del Rio.
The Jaguars probably wont be very good this year and Del Rio will likely take the brunt of it. He doesn't have the big-name publicity that the Grudens, Shanahans or Cowhers have (or the rings, I know...but I'm trying to think like Ralph here) but he has had decent success and is very much a disciplinarian.