My understanding is that Tonya works with the Outside hitters, while Erik works with the MB blocking, back row defenders, and overall defensive schemes/scouting reports. Jerritt runs the overall offensive scheme, and I believe setter coaching duties were deferred back to him when Salima Rockwell returned to Penn State.
With Salima in charge of setting, players like Engle, Kocher, Allison, Dalton (when she physically able to) and Collins developed into pretty good setters. Some may argue that Hannah was a terrible setter, but I think a lot of that had to with the high-jumping players at the time who liked hitting high, slow balls like Haley, Bailey, and Khat. Even when Salima left Collins' Jr year, she was coached by Evan Sanders (a setter coach), who was a volunteer assistant at the time (and now an Asst. Coach at Colorado). By her senior season, Chloe already knew what system Elliott wanted to run and was comfortable doing it without needing much technical guidance.
Unfortunately, we are now seeing what the setting looks like without a coach with technical setting experience. I really do think Shook has the talent, but she appears to be the type of player that NEEDS someone consistently coaching her up. SPVB (her club) is known to put out great setters because they are technically drilled and get an obscene amount of reps with their intense training...literally, setters coming out of that club are often called 'SPRI robots'...but it's obvious Shook's training hasn't translated well to the college game.
Even though it seems we get whoever we want (because we're Texas), that wasn't the case when Jim Moore took over for Mick Haley in the late 90's. Texas Volleyball was abysmal during the Moore years and it wasn't until several years after Elliott arrived that the program began to prosper again with his recruiting classes.
But I do agree that Elliott needs to rethink about upgrading his current staff with individuals who can coach setting and improve the defense and ball-control/passing...because those continue to be areas of weakness.