In their own way, both Mike Zimmer and Bill O'Brien are descendants of the Bill Parcells coaching tree -- Zimmer spent four seasons with Parcells during his final coaching stop in Dallas, while O'Brien began his career as an offensive assistant for Bill Belichick. The similarities between the Minnesota Vikings and the Houston Texans, then, shouldn't be all that surprising.
Both teams reached the playoffs last year with bruising defenses that made up for underwhelming offenses, and both are led by men who became stars on HBO's "Hard Knocks" for their command of a certain kind of vocabulary.