Agreed, it is a completely ridiculous assertion by Scheidel. You have to wonder at the shallow knowledge of the particulars that would have lead him to this con

Agreed, it is a completely ridiculous assertion by Scheidel. You have to wonder at the shallow knowledge of the particulars that would have lead him to this conclusion and the confidence with which he makes it. The Mongols left because their attention was diverted by leadership succession issues. Castles did not stop them in China or the Middle East. Fragmentation did not stop them in Central Asia or the Rus.