score:11
The mongols, when at their best, were unified and powerful. At the time, Russian city-states and kingships had little to no unity, and as the mongols were the top dogs of their time, they easily dispatched the little true resistance they were given. Plus, much of Russian land is plateau. The mongols were given a big boost with this as their horses and archers achieved maximum results under these conditions.
Mongols were also very self-sufficient and never lost troops easily. There have been (true) stories on how one scouting party sent by Genghis Khan nearly annihilated all of Eastern Europe and West Asia. They could survive in near intolerable conditions like Russia and Mongolia due to generations of living off the barren land. They also picked up new troops nearly everywhere they went as the Khans were very tolerant of caste and religion, as long as one also worshiped the Khan. Many great Mongolian troops and generals were farmed of conquered villages and states.
In hindsight, it may be confusing to some people seeing Russia as the big power it is today, but Russia was just groups of weak states at that time.
Upvote:9
Just a couple of thoughts.