He was much more than fine at ND. The RB position underperformed before he arrived with barely anyone reaching their potential let alone exceeding it. Theo was the only guy that definitely reached his potential. Maybe Cam too but he had some key bad moments. Atkinson, G. Bryant, and C. Wood never actually hit their potential, and fundamentals, especially ball security, were a huge issue. Then Denson arrived and he got the best out of every player he coached. Josh Adams had the greatest freshman year in ND RB history. Prosise was developed into a 3rd round NFL draft pick in his 1 and only year as an RB under Denson. Jafar Armstrong actually looked like a good back in 2018 before he got hurt, but then looked like he had no idea how to play the position after Denson left the following year. Dexter Williams struggled with injuries and inconsistency but Denson kept developing him and he went out with a fantastic senior year. Even Deon McIntosh showed huge potential under Denson before getting into trouble.
Every RB Denson coached at ND met or exceeded their potential. . He did a great job teaching basic running and blocking fundamentals and eliminated fumbling entirely from the position group. He was much better than fine.