Matt can speak for himself on this...but I took from his essay that his decentralized idea means it’s not like the Roman Catholic Church with a specific power structure, accreditation, etc.
It doesn’t mean that there aren’t players looking to improve their station in islam, by coordinating attacks in furtherance of the over-arching goal.
Imam, mullah, sheik, isn’t conferred by degrees in theology, but by success in terrorism and the number of followers.
I agree. Besides, the larger message is the infiltration with intent to do great harm, whether at each jihadist's opportunity or as part of something coordinated. They are united in purpose, that is beyond debate.