Why not Chad Pennington? Bring him in to help with Mark Sanchez, even to consult.
As a Rhodes Scholar finalist, he is one of the smartest players ever to wear the Green and White. As far as decision making, he was one of the best. Whether you liked Chad Pennington or not, you couldn’t argue with his decision making.
Having the highest completion percentage ever is clear evidence of that.
You can argue whether or not Chad Pennington had the arm strength to make all of the throws. Not an issue, because this is not Mark Sanchez’s problem. His problem is with his decisions, and Chad Pennington would be as good of a force as any in teaching Mark to make better ones.