ARE YOU KIDDING??? Sweetie, if you want to be taken seriously, don't ever, ever quote Janne Gillou as a source in historical matters. He is a very excellent journalist that specializes in fiction novels, but he even admits himself that they are not based on actual events. They are based on things that could have been possible, which is entirely different from what actually happened.
My opinion as an archaeologist is that the Swedes were just as scared of the Norweigans as the Norwegians were of the Danes, who were just as scared of the Swedes and so on. They were one and the same people, but different regional groups existed within the areas. The countries as we know them were not countries back then, the part that was Norwegian one week would be Danish the next, only to become Swedish a few months later and then back again, depending on who killed/formed an alliance/married/hated whom, where, when and why. You can't make blanket statements for the whole area, and even at that, it's a two way street: the dragonships of, let's say, the Svear, were just as fast and lethal in shallow water as a dragonship owned by someone from Rogaland or Jellinge. The construction was the same, save the size, which varied depending on a number of things.
The only people I can think of that most Norsemen were intimidated by would have been the Finn "magicians", because they were thought to be more powerful than the Norse Seidkonor.