Pretty much.
The analogy I am fond of using, is, Imagine the Offensive system Reid teaches/coaches is a math class and he's the professor. All the offensive coaches under him are his students, "learning the math." Some learn it just enough to do the problem, others actually learn how it works and WHY they get the answers they get, which allows them to figure out just about ANY problem because they understand the concept.
Then you have Nagy, who's the one kid who slacks off every year and skates by, by finding someone who took the class before and copying the answers to the test questions for the easy A, while actually understanding NOTHING about the class.
He's fine so long as the problems he faces are from those tests he memorized.
But second they deviate from those tests - he's fucked.
Basically Nagy learned and copied the plays, but had no fucking clue how to use them, how to adapt your talent to them, and got exposed as essentially "cheating on the test" to get hired as a HC. THAT is the level of incompetency we were dealing with.