Early in his tenure, I would have chalked Tomlin's mistakes up to this being his first HC gig and he was learning the ropes. Lots of guys don't figure it out in their first three years, get fired, and come back the second time and succeed (Belechick, Carroll). It's been eight years now. By this point you either get it or you don't, and I don't think he does. There are worse options, and the question I always bring up is "Who is available that is better?" And as Pittsburgh knows, that answer is Cowher. He's not the X and O guy like Belechick, but the man has produced results on his own and not on Noll's coattails. I just don't see Pittsburgh ownership doing something unless things get real bad for an extended period of time. Tomlin's worst year is still better than Cowher's worst years.
The Eagles played 4 backups on the o-line yesterday IIRC. Only Atlanta was more beat up, as they had a TE playing RT the entire 4th quarter.