Keira Knightley as Guinevere ready for battle. I think that the Picts could have gone to battle in very light armour such as these, but in the case of the women, the breast protectors would've wanted to protect all their breasts, not to show them off. That's not the aim of a breast protector! Apart from that, it's realistic for a very light warrior.
I know this is made to look more viking but the underlayers with the long chemise, open coat, and boots and pants is actual more middle eastern. Same with the front and back armor harness over chain maille.