Your usage of the word dominate and the usage of my word, controlled, are completely interchangeable. So what point are you making? "No, they didn't controll the north Atlantic, they controlled alot more." Well it suits my cause. So why are you arguing?
He actually told you the difference between the terms in his post.
Something about how "control" would imply that the Vikings would be able to keep other people off the land, which they never did except in England.