No, not really. The Vikings will not overrun anybody unless threatened, and the Vikings will stay quiet with their own affairs for the long years to come.
Only Catherine has a price to pay and the Vikings will repay a debt to the Egyptians, who suffered a devastating war due to a Viking diplomatic mistake.
By the way, Catherine already has Cuirassiers and Musketmen. But, for the Vikings, Cuirassiers and Musketmen are starting to be a thing of the past, as the new units coming from the barracks are Riflemen, Cavalry and Cannons!
All looks like MAGIC to my people