I dont think the Defense staff should be in over their heads teaching the Defense. Just making sure each level of the defense knows their responsibility and communicate to be on the same page. That is not specific to the 3-3-5, that is for any defense. Bob Diaco struggled for many reasons, personnel (going from 4 front Pelini and Banker to 3 Front), practice structure, adapting defense to style of play, etc..... Tony White has talked about it but personnel will dictate your defense. If we dont have good LB's and are good up front you will see more 4 front alignments. It will be White's Job to structure his install, drill progressions, meetings to inform the assistant coaches what needs to be taught and how to teach it. You reevaluate this daily.
For the Texas HS coach. He was a Head Coach that ran a team and was in charge of the performance of players and coaches from all 3 phases. He is not being asked to call the offensive plays. He will be teaching his TE's how to operate in the Run and pass game. I am sure he is 100% qualified to teach what is asked from our TE's to perform in the offense. I bet he brings a unique background knowledge from all of his years performing his HS duties that can come in handy too. There are some very innovative coaches at the HS level too. Also, Nebraska has had trouble recruiting Texas since joining the B1G and this may be a guy that can get us back into one of most talented football states in the country. I would consider that a win.