I recently read Jack Weatherford's Genghis Khan and the Quest for God and Genghis Khan and the Making of the Modern World. Weatherford points out Genghis Khan out for his own contribution to religious freedom. Also, his dynasty has a long reach.
First, many Chinese-appearing artifacts are Mongol appropriations of Chinese work. To fit in, Genghis and his followers would have artwork make in Chinese style garb. They would also take names that appeared more Chinese.
Second, Genghis Khan's numbers of vanquished foes were great but likely exaggerated to reflect the times. Many militaries kept greatly exaggerated numbers at the time, but Khan's numbers (even if exaggerations) were larger than others. This may reflect a larger truth.
Third, Genghis Khan appropriated both religious belief, cultural ties, and followers that were great craftsman. One of Khan's generals and closest confidants was a man who had shot one of Genghis Khan's horses through the neck. Khan liked what worked, and gained literature and culture through hiring vanquished men.
These books taught me a great many things about the time and culture of the Mongols.