That scheme is actually butter once you get it because of how flexible it allows the QB to be. But he is a good OC and I believe most would agree with that consensus. He had Mac Jones looking like one of the next best things his rookie season. And that offense was 6th in scoring and 7th in red zone conversion rate. That's how he got he Las Vegas job.
And while Carr rewrote his story with Gruden, it shows that most of the league really care little about substance and more of the appearance of production. Carr was racking up yards, completion percentage and near the bottom of the league in TD%. That was the first thing that caught my eye more than anything and diving into that is how I tied that to how bad he was in the red zone during the Gruden years. I think he adapted better to Gruden's system because it was closer to what he was doing under Del Rio/Musgrave but that still took time.
That's why I always talk about perception.