Good point. A little trivia:
Weeb Eubank is the only coach to win NFL championships with two different teams (Colts and Jets.) He also coached two HOF QBs, Unitas and Namath, winning championships with both..
Shula is interesting. He coached three HOF QBs, Unitas, Griese and Marino, but only won championships with Griese, the least heralded of the three. Course, he had Unitas at the end of his career.
Shula and Landry both had teams that peaked just in time to get raided by the World Football League. The Steelers gelled shortly after the WFL tanked, and didn't lose players, allowing them to keep their core together for their entire run.
One thing that makes the Belichick-Brady partnership unique, is that they've hung together for going on twenty years, and the only people left from their first Super Bowl win are the owner, Brady, Belichick, I think one trainer, and probably the guy that sweeps the place out.