I used to mosey by the R.O.T.C. office in the bowels of Winston-Scott back in the day. On one wall was a series of pictures, denoting the chain of command. It was a simple reminder of who was in charge, and in what order.
To gaze at the chain of command at TCU, AD sits over the Head Football Coach. Theoretically, he can fire him should he choose to do so. However, as you point out, there are practical considerations that do not show up in the simple chain of command.
Today, November 17, Donati may not have the backing of the restless herd of backers who, just 10-15 years ago shelled out literally millions to build that magnificent Stadium. As Del Conte said at the time, "Gary did the talking, I just followed along and collected the checks." We're not a "What Have You Done For Me Lately" outfit and never have been. But repeated, avoidable failure is galling. That support is not what it once was.
As a Program, we cannot have incompetence ruining our product. All involved understand this. It must be made clear that further failure is not acceptable. Playtime is over. And the only way to achieve the successful transmission of this message is for the recipient to know that he is out of residual goodwill.