No, Rumsfeld was Bush's best decision.
Rumsfeld saw clearly the need to transform the US military from an obsolete Cold War fighting machine into something more lithe and nimble, fitted to meet the enemies we face today. More than that, he could had the courage and the backbone to actually DO IT.
The entrenched careerists in the Pentagon didn't like that. Tough beans. They deserved to have their chops busted.
You don't accomplish doing that by running troops and equipment to death without allowing for replacements and equipment upkeep. What part of that can Rummy and congress not yet comprehend? If Rummy on 9/12/01 had went to the POTUS and before Congress and said we are going to war and we need more troops. Then you might be right. He would have gotten them too. Why didn't he? Why you tell me does he insist on running what we have left ragged? That includes troops on third Iraq deployments.