Hiestand and/or Brewster would both be upper deck grand slams as part of the staff, but I would be leery of giving either one (or both) OC-type responsibilities when neither has done that in the past.
We know Lovie. He may well embrace read option principles, but he is not going to run a crazy tempo, he's not going to throw the ball all over the field, he is going to want to run the ball, control the game, and let his defense choke the life out of the opponent. Zany offensive schemes give you some margin for error. We're going to have to be excellent in schemes and game-planning and execution to move the ball effectively. Hiestand is as good of an offensive line coach as there is anywhere in football and Brewster is a nationally elite recruiter, but the fact that both guys are such renowned commodities and neither is a coordinator at this stage in their careers tells you something.