The freaking Rus horse archers are 80 foods, 40 woods, 23s, while mangudais are 90 foods, 60 golds, 28s. But the mangudais’ dps are only SLITGHTLY higher than horse archers(a value between 0.5 to 0.9), while they also have 1 tile shorter range to shoot. Which means, I need to always produce at least 1 more unit, to fight a CHEAPER unit, if I want to have the same range compared to Rus HAs then I need 1 Khan’s hunter at least but dude does 0 damage almost. Or a Khan following mangudais, but arrow cd is a problem, and that is still at least 1 more unit anyway. What a riding horse national. Rus just makes me feel they are more horse riding.
Rus is a Calvary civ they’re as Slavs on AOE2 and here. The major difference is that Mangudais can attack while moving.. this is a major difference and it makes them extremely dangerous.
Two other points that I will point out are for Mongol is that they get their Mangudais at Feudal Age where as Rus get their archers at castle. This is a big big game changer if you can pump out 6-10 mangudais and raid a forward gold you can pretty much end the game right there.
Mongols have a high skill ceiling and Rus isn’t very hard for them. Mongols will have a hard time with Ottoman and OoTD/HRS M@A rushes but again they’re probably the harder civ to play properly at all ages. Having a dark age where you can play big aggression makes their learning curve unique.