It's both happening at the same time. Maddox is cooked. But that's not even half of it.
To play in a Fangio defense, you need time with it. It's a relatively complicated system made to look as simple as possible. So when you chart it by coverage type, it may not look all that different from what they did last year.
But coverage schemes only work as well as the execution by your weakest links. Most Zone Snaps aren't just Spot (go to your spot) schemes anymore. There are match patterns and rules to them. When you hear something like "Shanahan broke the rules to that defense," this is what they mean. The defender followed what he was supposed to do, but the offensive scheme/play meant it was an impossible situation for the defender.
Look at Kevin Byard being back to a solid player in Chicago this year when he's not saddled with Matt Patricia's oversight. Defensive coaching requires not just communication with your players, but teaching them to communicate properly with each other in real time. The only way to do that is with live reps.
