Rather than a direct translation of Shakespeare, the authors have done what he did: tell the most exciting bits and make it relevant to the audience of the day. If I have any criticism of Shakespeare’s work, it’s that many of his stories are told in fast forward. Such is the nature of a stage play. In this case, the story is expanded so as to tell what a stage play cannot, delving deeper into character that dialogue can, and depicting battles that might otherwise get glossed over. The result is a wonderfully told story of which I daresay the bard would approve.
Another point worth mentioning: the biggest issue I have with modern performances of Shakespeare is the incessant need to modernize the story and take characters out of their historical context. This version places the story in Medieval Scotland and makes it feel real. There is a verisimilitude to it that draws you in and makes you believe it.