I'll provide 3 reasons RR needs to dial up Charlie, regardless of whether or not he is looking for a new job. You never know what can happen or if RR has any Clemson snake oil still.
1) Per the GERG, we are looking for a secondary coach and not a LB coach. Charlie coaches the secondary.
2) Charlie recruits in a geographic area that we are focusing.
3) Charlie made the Rivals Top 25 recruiters in the nation (H/T to Doc Sat for the original link), his bio is below.
CHARLIE HARBISON, CLEMSON
Buzz: Harbison had a banner year for Clemson, pulling three prospects out of Georgia and three from Alabama. In Georgia, he won the battle for Darius Robinson, Corey Crawford and David Beasley. In Alabama, he took away Desmond Brown, D.J. Howard and Demont Buice. In a year where a lot of prospects in the state of South Carolina left home, Harbison's out-of-state efforts were key for Clemson.
In the absence of any other announced candidates, why not?