I am going to say something that is not going to make me popular. But why is a female protagonist needed? In a lot of cases it makes more sense to choose a man for these kind of games. First of all, a tough bearded viking is probably going to sell better, that just how it is. But let's be honest. When you look back at history most of the fighters were probably at least for 95% men so it's also logical often that you choose a man for a action/fighting game that takes place in history. And yes I know there were also a lot of female Viking fighters, but pretty sure most of them were still men.