You are correct to a point, BlackSport, but don't forget that when the generals were putting together their invasion plan they told the administration how many divisions they wanted, and the administration (Rumsfeld) said "No way -- we'll give you two thirds of that."
So the critics who say we didn't have enough boots on the ground are and were correct. In fairness to Shrub, although I don't like to concede this, I don't think it's really his fault (except in the "The buck stops here" sense). He relied on his Secretary of Defense, and Donny was fanatically committed to using technology and machinery rather than manpower. What this translates to is that Shrub was given bad advice by his SecDef, and being a flyboy rather than a ground pounder, he can't be entirely faulted for not overruling Rummy.
Of course, in retrospect it appears that even the number of troops originally requested would not have been enough to secure the country after the invasion had been completed. If they had another division available at the time, could/would they have detached a company or a platoon to secure that particular site? Who knows.