Yes. I think he overlapped with Schnellenberger for the '83 championship season. I used to wonder about that relationship. Two very strong personalities, wouldn't be surprised if they clashed and maybe Howard did not want to work under Sam. So he left.
Sam probably would not have hired Larry Coker, Randy Shannon, or Manny. Sam was adamant about not hiring as a head coach someone who had never been a head coach. He had had a very bad experience at one of the schools where Sam had previously served as AD. I don't know any of the names, I just remember Sam telling the story. He was insistent that he would only take someone who had a track record as a head coach. That being said, I never understood why he hired someone as obscure as Jimmy Johnson. Jimmy had a mediocre 30-25 record at Oklahoma State.
Turned out to be a great hire. Maybe Sam saw some things that were not obvious to most. After all, as far as I know, Sam never had any connection, coming from the Pacific Northwest, to the Frank Broyles-Johnny Majors-Jackie Sherrill coaching tree which was Jimmy's background.