Well, there is one interesting incident regarding Mongols and city dwellers and nomadism:

Chinggis Khan promulgated a legal code that was enforced by a special police force. Much of the code was aimed at putting an end to the divisions and quarrels that had so long occupied the Mongols. Grazing lands were systematically allotted to different tribes, and harsh penalties were established for rustling livestock or stealing horses. On the advice of his Chinese counselors, Chinggis Khan resisted the temptation to turn the cultivated lands of north China into a vast grazing area, which of course would have meant the destruction of tens of millions of peasants. Instead he ordered that the farmers be regularly taxed to support his courts and future military expeditions.

(http://history-world.org/mongol_empire.htm)