Much of the territory that you have moved through so far is already inhabited by other nomadic tribes with no allegiance to you, and with no true cities or strategic centers under your control in this new territory, you have trouble holding it. Your eastward expansion is hindered by the fact that you are not the economic power that you could have been had you taken more profitable centers of Jin territory, and your eventual empire is but a shadow of what it should have been.
You chose a non-historical decision! In real life, Genghis Khan utilized many deserters from other civilizations to gain knowledge. Read more about how your decisions differed here.