think he's got the broad strokes correct. This from your link:
"The artificial constellation of the so-called “moderate coalition” under Maliki is to a large extent the result of a weaponry-focused American misreading of the many channels of Iranian influence. This was best summed up by Ryan Crocker’s comments in the US Senate on 8 April: in an attempt at playing down the significance of Mahmud Amadinejad’s popularity in Iraqi government circles, Crocker referred to the staunch anti-Iranian attitude of the Iraqi Shiites during the Iran-Iraq War. What Crocker failed to mention was that his own administration’s main Shiite partner in Iraq, ISCI, is the only sizeable Shiite party that fought on the Iranian side."
is, I believe correct in essence but wrong in detail -- at least in one detail.

The problem is not that the US is "weaponry focused" (whatever in the world that's supposed to mean); it is, as I pointed out a couple of days ago, that our prime "Arabists" continue to misread the nuances in the AO; they see what they hope to see as opposed to what is.