have been great when working for Meyer at FL or OSU and also for Holtz when he was at SC. Meyer couldn't save ND under Davie. The head coach can drown out even the greatest of assistants.
We typically say our OL coaches suck because we can't run block. However, it is the head coach that prevents the team from practicing running plays, not the OL coach. The head coach decides how much time is spent on special teams, not the ST coach.