I really hope that no one is planing an IO campaign using a "rats leaving the sinking ship" metaphor, because it won't work. In fact, it will backfire badly and just reinforce the determination of the current members and expand their recruiting base. What might work, although it's a lowish probability, would be trying to make a symbolic tie in between the Mahdi army leaders and the Mongol governors from the 12th century or, possibly, a tie into the Ottoman period (maybe something tying into Murad the Mad's period - ca. 1630).
An excellent point I had not thought about, and a concrete example of the sort of inputs that would make a CST http://council.smallwarsjournal.com/...ead.php?t=2063 valuable