Bruh.
At the Battle of Nicopolis, they had twice the amount of troops the Crusaders did, and they still managed to win while losing most of their army. Not only that, but you had like 20 different countries and principalities that were fighting as a force with like 10 different languages versus one homogenic army with three random serbs here and there who all spoke the same language and had the same training
Not to mention the fact that Nicopolis is highly fortified position with great natural defenses, the crusaders didn't even bring anything to siege with, and during the Battle the French fucked off on their own and basically lost the whole thing for everyone else because they were too cuntish to follow the general strategy.
That's like the worst fucking example of the greatness of the ottoman empire it was a bunch of retarded frenchman who fucked everyone's shit up by running straight through stakes dismounting then getting their shit kicked in instead of waiting and letting the enemy come to them where the crusaders could have easily won if they had waited.