Agreed but this has very little to do with your previous point. None of these things means that the owner and CEO do not ultimately hold the reigns, it only means that the manager doesn't hold them at all. At the moment we know that the manager provides a list of targets and that a group of people comprising the chief scout, Murtough, Judge, Woodward and maybe other people approve the list and try to get the targets.
In theory a DOF would change nothing for the Glazers and Woodward but it would change a lot for the rest because the DOF would be the only interface between the head coach and the board, he would be the main driving force and have seniority on everyone but the owner and the CEO. People that have the idea that it is Woodward/Glazers who are against that should think about it this way, who are the people within and around this football club who think that the manager is supposed to be a demigod?
Personally, I believe that the Glazers and Woodward are cowards and afraid to upset certain figures by turning the manager into a simple employee. They think that by maintaining the SAF/Sir Matt Busby role, they are protected from the traditionalists.
Of course, it could be confirmation bias and I'm totally wrong.