That's an interesting comment regarding Garrett's skills given that Coach Hoiberg basically said the opposite at his intro press conference. I would agree with Coach on that one.
There were several things that led to GMac's struggles at ISU, but I don't think a strict offense and too many set plays had much to do with it.
The number one issue was losing Wesley Johnson and the manner in which it affected GMac's coaching and his player relationships, especially last season when he had enough talent on the roster for the first time to compete for a post-season bid. Pollard touched on this after GMac left for Creighton, GMac treated Brackins differently than the rest of the players and the others on the team resented that. Throw in a high mainteance kid like Colvin (also disliked by his teammates) and you had a perfect recipe for real bad team chemistry.
Another big issue was lack of quality guard play. Mike Taylor was the only high quality guard during GMac's tenure and, by default, he had to handle the ball way too much and became a turnover machine in Year 1. Poor guard recruiting by GMac was a killer for the program and that helped result in high roster attrition from the likes of Buckley, Eikmeier, Brister, McIntosh, etc.
Regarding GMac's on-floor strategy and coaching, I thought he did a good job his first 3 seasons with limited talent and injury issues, especially in the guard court when he lacked consistent, quality PG play. This past season, he got away from what worked for him at UNI by playing an extended man defense (which he ditched halfway in the conference season) and by running way too many isolation sets for Brackins which ended up stifling ball movement and player motion (and played a part in bad team chemistry).