As far as retreads go Tom Herman may be the best option.
Houston 3 years before Herman: 5-7, 8-5, 8-5
Houston with Herman: 13-1, 9-3 (6-0 vs ranked opponents, 3-0 vs top 10 opponents)
Texas 3 years before Herman: 6-7, 5-7, 5-7
Texas with Herman: 7-6, 10-4, 8-5, 7-3 (finished ranked last 3 seasons, 8-6 vs ranked opponents in those 3 seasons)
Never has had a season that wasn't better than the situation he took over. Has proven he can beat good competition at multiple stops. 5-1 in bowl games. Was Ohio State's OC when they averaged 48 PPG through the Big 10 championship, playoffs, and natty with a 3rd string QB.