The challenge is that I firmly believe that building a winning club needs more than good coaching. You need good ownership/team management and good player acquisition.
And I think several of the Cowboy coaches have suffered due inadequacies elsewhere in the organization.
Joe Torre wasn't considered anything special as a manager until he went to the Yankees and had the privilege of having solid ownership combined with a smart GM in Cashman. Joe Torre is a HOF now because of what he accomplished in New York. And that accomplishment wouldn't have happened without the other "two legs of the stool" being in place.
Garrett isn't the CEO. The CEO has the ability to call all the shots, which of course he doesn't or can't. And the true CEO isn't likely to change his spots any time soon.
He is the CEO on the field and that hasn´t brought any good results either as you know.
Talking about legendary coaches doesn´t make sense, for every Landry, Belichick or Torre there are a thousand mediocre ones, and that´s where Garrett belongs as of right now, hope he can prove most of us wrong.
At least Torre was a 9 time all-star player, MVP award winner in his playing days, as a coach he had 15 years of experience before getting to the Yankees (as we know Garrett is learning on the fly), look at the Yankees with and without Torre while Cashman is still the GM.
Anyway, I hope Garrett ends up winning coach of the year and then coach of the decade by all means (while being in Dallas) but right now that is more than wishful thinking.