Answer:
We can compare the Mongol Empire with the British Empire in three ways:
The Mongol Empire did not colonize as much land as the British Empire.
Several reasons account for this, first, it's a demographic problem: the Mongols were less than the British, so they did not have enough people to populate conquered areas.
Secondly, the lands the Mongold conquered were already inhabited by other ethnic groups and there was not a lot of room.
The British Empire founded colonies in areas that had sparse population: Australia, Canada, the United States, and thousands of colonists emigrated and found room to establish farms.
The Mongol empire was interconnected by land, the British Empire was interconnected by water:
The entirety of the Mongol Empire was located in Eurasia, and spanned across deserts, praires, plains, mountain ranges, and river banks. The British Empire included territories all over the globe, in the five continents, and was held together thanks to the might of the British Navy, by far the most powerful navy at the time.
The British gained more wealth from the Empire than the Mongols:
The height of the British Empire coincided with industrialization. In a positive feedback loop, the British extracted raw materials from their colonies, and transformed them into finished goods and services. This brought enormous wealth to Great Britain.
The Mongol Empire on the other hand, did extract wealth from their colonies, but as they were not industrial yet, they did not so to the same extent.
