I think idea of holding elections sooner being the answer is mostly wishful thinking. Whereas focusing on building Iraqi security forces quickier may have been a major mistake.
The idea of holding elections sooner is just full of huge holes in logic:
Is it not true that Saddam regime had planned fighting after Coalition had defeated Iraq in conventional war? Is is not true that the "insurgents" were strongly supported by piles of cash and foreign fighters? And the other major element being Saddam ruling elite?
This "insurgency" simply was not a insurgency because the term implies a popular uprising with some form political grieviance, no this was a counter offensive- covert warfare employing terror tactics- & propaganda. This was how Bin Laden was planning on defeating Saddam army "defending" Saudi Arabia in 1990s. This is how the CIA fights a war -and they learned it from the KGB, who learned from British and French. Nothing really new here, nor nothing particularly smart. It's basically playing chess by copying your opponents moves. So if your opponent is building schools, you destroy schools, fixing sewers, you destroy sewers, ect.
Once, you understand the stupidity of this tactic, it's pretty easy to defeat it. But you really don't need to defeat this plan, because in the end it's self defeating- it's at best a delaying tactic. It's not a winning strategy- nor has it ever won. But it can destablizes a weak govt. For instance it wouldn't work in America [you think *someone* didn't try it!!], nor will it work in Iraq. Though it might have worked if we had held elections sooner.
Building an Iraqi army sooner, would mostly be for political reasons- to address the main political concern of Iraqis- security concerns. Security concerns are not really addressed by having a strong foreign miltary presence in your country.