I hesitate to simply put everything at the feet of Mike Sherman. Friends I know who are fans of Green Bay and aTm warned me as soon as we hired him. They have pretty much been dead on in their predictions of what I would complain about. But at the same time, I realize that the offensive coordinator still must work with the personnel he has been given, and I do not think the offensive unit is good overall.
Now, I do absolutely believe he needs a QB coach with a good track record and real experience. I do not understand why you would pick a 'raw' quarterback #8 overall, knowing that he needs real development, and then bring in a young guy with no track record of coaching QBs to try to work with him.
HOWEVER, Ryan Tannehill is showing growth and improvement in his game. We don't know whether he is showing that growth and improvement as a result of his own talent and ability to learn on the job, or as a result of good coaching. We don't know if he could be improving faster with better coaching or if he just needs time to work at it. In other words, I got no clue.
Personally, and as much as it sucks to say it, I think he just needs time. In order to master any skill, it just takes time. In high school, he was in a very run heavy offense in which he didn't throw the ball much, and when he did it was often bootleg type of stuff. In college, he spent two years playing receiver. Unlike Andrew Luck, he didn't have the benefit of being coached from the time he was in grade school by an NFL quarterback. The big question here is how much time this team is willing to give him. I think he at least gets year three.