This is basically how Mongol DNA spread all over Asia.
A friend of mine has PhD in history and his doctoral thesis was on the rapid spread of the Mongol Empire. There were several reasons of why and how this happened, but one that was mentioned was that Genghis Khan changed the nature of how a defeated enemy was to be treated. Historically, a defeated enemy was dealt with harshly (Men and boys killed, goods pillaged), but by and large women and girls... while not being treated with kindness, were often left alive.
Khan changed that... if a city or state submitted, then they were left with a governing entity and required to pay the Mongols... they could keep whatever god they wanted to worship, rulers were left in place, they might be a little poorer than they were before, but they were allowed to just go on with their lives and culture.
If they refused to submit, and Khan was required to fight them... he totally whipped them out... killing everyone, men, women, children, animals... stripped the city and raised it to the ground. Of course this got out...
When approaching a city, Khan would send spies and the first thing these spies did was connect with women, in fact many of his spies were women.... the women heard the stories about what the Mongols did when they conquered a city, they knew that if their men resisted, they would suffer the same fate as the men, they would not be spoils of war, they would be killed. It was the women that would use whatever influence they had to compel their men to surrender. There were several stories where the wives of rulers helped others assassinate their husbands, who were leaders and had the intent to resist Genghis Khan. There was one story where the wife and concubines of a city ruler had him and his major lieutenants assassinated because they planned to resist the Mongols. The women would encourage their men to rebel against the leadership and often when Khan road up to a city the former leaders where tossed over the wall.