It's Debatable
You are quite right that no war plan survives unchanged, but there were plenty of people warning of scenarios quite similar to what happened. I doubt very much that you could have planned seriously for such a possible outcome and failed as badly. I think Bush's group think team tended to believe only the rosy scenarios and planned accordingly. They certainly have demonstrated numerous occasions that data is irrelevant to what they believe when it comes to science or economics.
I have to agree that the actual battle plans of Bush's team far exceeded anyone's expectations and they deserve credit for that which most Democrats would prefer to die before doing.
Regards,
Mark