1. Quite a few nations famous for their military should instead be famous for propaganda. Their military track records are average to subpar, and rarely as dangerous as their enemies feared. Some of the examples are Sparta, Russia, and China. Sparta's track record is slightly below average, and they rarely won any wars alone. Through a good chunk of history they were puppets or partners of Persians as a counterweight to Athens, Thebes, and Macedon. Russia often needed help of another major power to win any war that was not against an opponent that was magnitudes weaker on paper and even struggled with reigning in Chechen. Chinese were conquered by foreign invaders multiple times, and back in the 80s they were humiliated in a war against Vietnam. However, all of these nations were good at propagandizing and especially playing up their military power.
2. Mongols were not as powerful or meritocratic as many say. They spent decades trying to subjugate China, and their successes in Europe were reliant on outnumbering their opponents and surprise attacks, usually on weak nations struggling with internal crises. Mighty mongols did not do so hot once they had to face proper European knights. When Hungary recovered from Cuman crisis and finished their reforms, and Poland ended its civil wars, they were able to halt Mongolian invasions. If you lived within the Mongol empire, your were more likely to become a slave or get executed than rise within their "meritocratic" system.
3. China and Middle East were not as far ahead of Europe in 1200s and 1300s as it's often made out to be. At least in some areas like military tech for example. Mongolians were able to crush Chinese and Arab cities and fortresses, and yet they failed against European castles. That's despite having siege engineers from China and Middle East in their ranks.
4. World would not be a high tech utopia if Christianity never took off. Quite the contrary. After western Roman empire fell, it was often the church that was the one to pick up the pieces and preserve as much knowledge as possible. Public education, libraries, universities, scientific method, artwork, agricultural innovations, and much more developed thanks to the church. Later, many great minds of enlightenment were motivated by religion. They believed that the best way to honor God is to study his creation.
And medieval period was not nearly as "dark" as it is made out to be.
Russia was a mistake. t. a Finn
It's kind of hard to argue with this. Russians were the first commie nation. They promoted Marxism and critical theory abroad, thus leading to the current wave of globohomo. They signed Treaty of Rapallo in 1922 that let German military secretly train and build up in Russia to bypass Versailles Treaty for 11 years, basically handing Hitler tools to start World War 2.