Why were there a large number of Chinese immigrants in the Mongolian state?

The Mongol state consisted of many Mongol and Turkic tribes who were nomads. With a nomadic lifestyle, it is difficult to develop sciences and learn crafts. And therefore, the first ruler, Genghis Khan, cared not only about expanding the borders, but also about the fact that the people were enlightened and mastered the crafts and sciences. For this, educated citizens were invited from neighboring China, who taught local residents to read and write, also taught them crafts: making gunpowder, working with metals, making coins, processing stone and wood, and others. For this reason, the number of immigrants from China has increased in the country.