But the existence of this praetorian-like guard does mean that ISIL, like most cults, is an autocracy and therefore a community of obedience rather than a community of will.
And that there is a Shield of Islam means that the autocrat has to watch his own back. Of course one wonders whether the Saudis, Jordan or Egypt could slip a ringer into ISIS hoping to get close to the leader which would necessitate a body guard.
One thing about the Roman Empire's Praetorian Guard, emperors died at their hands. So Al Baghdadi needs close family members around him to watch his body guard.