Alot of what you say is true, as far as what was expected of him last year. However, he realized that he was the only guy in that secondary to have real ability to make plays. The others could understand their assignments but did not have the ability to make plays( in other words, they would cover the right guy, but coulldn't stop said guy from making the catch).
Whitehead at times was trying to cover for others, and trying to anticipate plays more than reacting to what was happening. Alot of times, because of this, he came off looking bad. If everybody is healthy come the fall, the secondary will be: Ford at FS, Whitehead at SS, Hamlin at one corner, Maddox at the other. Each of these guys, should be able to handle their assignments, and more importantly, as the best athletes on the team, have the ability to make plays.