First you got the instability. You cant play yo-yo with young guys and you must be consistent in their developpement, even if you are losing.
I taught that Norv Turner and his offensive staff where pretty competant. I guess nobody can survive a 10 games losing streak to finish a season, espacialy not under Al Davis.
Second there is the coaching expertise of Art Shell's group. I dont care if you are a HOF player, it is well documented that it doesn't make you a great coach. Art Shell took all his old budies that needed a job and diged his own tomb at the same time. Look at a guy like Joe Gibbs: he knew that in order to have success in his situation, he needed top flight/ NFL current assistants (Saunders and Williams) and needed to give them more responsabilities.
Tom Cable is a career coach that made his marks everywhere his been. That's what we need. Not some HOFer that never coached anybody.
By the way, your team use a zone-blocking scheme if I am not wrong, Atlanta did under Mora/Cable, so I guess it is clear that we are going that way to.