I don't know what percentage of Scandinavian women went viking, I expect it was small. Men are bigger than women and are stronger for their size. You can certainly find an exceptional woman who is stronger than the average man but if an activity is demanding of absolute strength such as rowing or fighting the number of women capable of competing directly with men becomes vanishingly small. Hollywood is bullshit. When it comes to fighting remember the maxim, a good small man can beat a bad big man but a good big man beats a small good man.
The Romans had female gladiators but they only fought each other or male dwarfs.