A few things I should clarify here.
One - I don't have a link to the original interview, I read it in Maxim over a year ago. General Franks very briefly touched on the fact that he and Secretary Rumsfeld had disagreed about how to fight the war.
Two - I think that what Rumsfeld wanted was not full scale combined arms warfare, but rather, an intensive air campaign, with SF types calling in precision raids, hitting soft targets all over the country, etc. Not merely a 'Delta Force in downtown Baghdad' mission, but a full scale (albeit low intensity) war. That is the impression I got from the interview.
I think it probably would have worked. Yes, it would have taken longer than three weeks, but also the war could have begun much earlier, considering there would not have been the significant forces buildup in the Middle East prior to the start of the conflict. Also, there would be no occupation, which is the biggest issue of contention about the entire war, I believe.