Of course, but the problem is that the drop from his level of play to the guy ranked #2 on the team was bigger than it should have been (Mangold), and the drop to #3 was gigantic (whoever).
I think Mangold had another All-Pro season but he got hurt and that counts against you and he had stiffs playing on the line with him and that is the biggest factor of all. Mangold is another player that will be as good as the team lets him be.