Sorry, but Groce has to be #1 and by a long margin. We were out rebounded by a smaller team (again), we were unable to stop dribble penetration (again), these aren't isolated incidents, they are reoccurring themes.
Groce's best qualities are talent evaluation and recruiting. He needs somebody on staff who can help him in the areas he struggles (teaching defense, teaching rebounding, in game adjustments, substitution patterns). Adapt or die.
Case and point, look at Crean's staff at IU. Tons of head coaching experience, to tell him things like I think Syracuse is going to play zone. I'm starting to suspect that Groce needs list level of babysitting and his current assistants are not up to the task.