It's been brought up several times about how Shula failed to build a good enough team around Marino for all those years. There were some good teams (1985, 1990, 1992, 1994) but they all had fatal flaws in either player size or scheme. Shula was a big believer in not drafting behemoths like the kind that Joe Gibbs had in Washington or Jimmy Johnson in Dallas, fearing that those big bodies would wilt in the Florida heat. To a degree, he was right, BUT it should be noted that when it came time for the Dolphins to match up against such big, physical teams, it was usually the Dolphins who wilted. Richmond Webb and Keith Sims were big, but not that nasty. Tim Bowens was the only really big player that I remember Shula drafting that played "up" to his size.
Shula did indeed try his best to surround Marino with enough offensive talent to win, but for every Troy Stratford, there was a Lorenzo Hampton. For every Fred Banks, there was a Scott Schwedes. For every John Offerdahl, there was a Jackie Shipp or Jay Brophy. For every Dwight Stephenson, there was a Billy Milner. The only constant in the talent evaluation department was inconsistency.
And yes, Shula was loyal to a fault with some of his coaches. Chuck Studley only lasted three seasons before he was let go, but Tom Olivadotti lasted far too long, probably because he and Shula were close friends, beyond just the job.