So, whether you're making a historical movie, a futuristic sci-fi movie, or a fantasy movie, is it too much to ask that you plan your battle scenes out in ways that make basic, tactical sense?
No matter the year, and whether we're talking about dragons or fighter jets, air superiority is freaking important.
No matter the year, if you're defending a fort, it's dumb to send your infantry outside of the fort to engage with the invading force. Why the hell did you build the fort in the first place?