You're kinda wrong. The notion that the mongols came in and used only force is wrong. The reality is that the people who lived along the northern Silk Road knew of the benefits the mongols provided and willfully supported them in their overthrow of the Kievian Rus. The mongols also provided a pluralistic approach to many things. The Vikings weren't even considered to be white until the 19th century when anglos made up the social construct of race.

The vikings also specialized in hitting areas with litteral no defensive fortifications. The english had placed their monasteries on the rocky eastern shores to prevent them from being overrun by the locals, as the local population would occasionally attack them, but since monks generally did not fight back, attacking them was sort of like attacking a university, whose students are armed with sticks, while the vikings had axes and swords. An axe typically beats a stick, particularly if the stick is wielded by a guy who mainly does yard-work for a living.