You can't blame Russ Brandon for the team's lack of success on the field. They have to find a competent GM who can instill a winning strategic plan, which includes finding a QB, and efficiently allocating the team's resources ($$ and draft picks) towards a winning program. To my mind, Doug Whaley has failed at this - he is a good enough scout, but he doesn't know how to build a team, has failed at it in multiple attempts, and needs to be fired.
You can blame Russ Brandon for the mysterious and, some would say, misleading way that the team operates. The constant stream of misinformation concerning the status of players and injuries is an insult to the fans and is borderline fraudulent. And the atmosphere within OBD remains toxic, as it was during the Marrone years, with a penchant for odd, destructive "leaks" that seem to undermine players and coaches alike. As head of operations (effectively), Brandon is to blame for this and if I owned the team, I'd fire him for it. I'd add to that list the complete incompetence of the team's PR and medical staffs (the latter perhaps is not under Brandon, but arguably he has some say in it).
If I were the Pegulas watching this clown show, I'd fire Whaley and Brandon (and Rex), for different reasons, at the end of this season. I expect some version of a housecleaning will happen, although as Bandit said above it will start with the hiring of a Head of Football Ops (a "Czar"), who will insulate the Pegulas from some of the dirty work that is required.
You need someone who can create and implement a strategic plan. It's not a myth.