almost every battle scene I see without fail has a bunch of guys running full tilt into each other with no strategy at all, no sense of placement, no idea what the purpose of archers, cavalry, artillery, or infantry are. It's just a miserable mess of nonsense every time.

I mean, to be fair, a lot of battles in the medieval age were like this. Artillery was barely ever used in field battles. Cavalry was used to basically form up and charge and that's about it. Most battles devolved into a chaotic slugfest. There wasn't really a lot of tactics, battles were usually decided by who broke first and whether the winner was too tired to follow them or not.