Because they knew they could do more and they would work because they knew they were getting money
A tlatoani and justices shared control of city-states. I think
The Battle of the Somme, also known as the Somme Offensive, was a battle of the World War I fought by the armies of the British Empire and French Third Republic against the German Empire. It took place between 1 July and 18 November 1916 on both sides of the upper reaches of the River Somme in France.
In a short term: the Mongols would have have the control over the lands.
In a long tern: either the European powers would not have conquered the other continents during the colonial time, or if the Mongols had done the same, possibly in the Americas and Africa Mongolian would be spoken today.