At one point you could trace every offense in the NFL to either Bill Walsh, Don Coryell, or Ron Earhardt/Ray Perkins. Meanwhile, almost every defensive coordinator in the NFL worked with someone from the Dick LaBeau tree or the Tony Dungy tree or the Bill Parcells tree. When NFL coaches innovate successful systems and concepts, other teams try to copy them immediately and eventually, the best branches from the original tree make their way across the NFL.
Evaluating what systems the teams in the NFC North will be using this year is a good way to foresee how the team will perform.