The high turnover of managers is the whole point of having a DOF. The position of DOF keeps continuity across the club and stops managers coming in and wanting the players to fit some system they favour, and then moving on and leaving the club with players that don’t suit the next manager. Under the DOF system, coaches are brought in who can work with the club’s style of play and players, when they move on another coach comes in who is happy to work within those parameters.
It’s just that our Iranian megalomaniac is not prepared to wind his neck in and appoint a new DOF and allow him to do his job without interference.