John Fox is in the third tier, essentially in a tie for 11th place, with this explanation:
It’s hard to know where Fox’s impact ends and Peyton Manning’s impact begins, but don’t overlook Fox’s hire of Jack Del Rio for a much-improved Denver Broncos defense.
In two years in Denver, I’m convinced Fox’s leadership is underrated. I’ve seen arguments that he isn’t a great X’s and O’s coach. Maybe (though I’m not convinced). But he’s as strong a leader as any coach in the league, allowing those on the coaching staff and on the field to excel in their given areas. The consistent answers given by players in interviews every week (“one week at a time”), and the apparent positive morale, show his influence and a motivating and empowering presence.