in that same period if you take into account both superbowl participants you can add
Pete Carroll
Ron Rivera
Kyle Shanahan
Belichick
Mcvay
Shanahan
Reid
Taylor
Sirriani
Shanahan
14/20 are offensive, BB is 4 of the 6 defensive examples, Ron Rivera was the 5th (with Cam Newton MVP as his QB) and Carroll the 6th
i think more notable is that it's basically the Shanahan tree and the Andy Reid tree offences that are appearing in most superbowls (or Tom Brady)
most of the most successful offences in the league are coming from those two trees (mostly the shanahan/mcvay tree though... 49ers, Rams, Bengals, Texans, Packers, Dolphins, Vikings - and the Falcons, Bears, Titans (by way of Kubiak), Raiders, Saints and Bucs are joining that tree too - which is nearly half of the NFL running some variant of that offensive system)