honestly, I don't think Charlie was looking that far ahead
In 2006 he had Jones, Frazer and Sharpley waiting in the wings, with Clausen coming on board in the springtime. Obviously, based on the minimal game time that Sharpley saw, he wasn't actively planning for Evan to take over. I assume he thought he'd just have a battle royale in the spring session, and let the last man standing have the job.