Installing mods for Warband is famously simple. Most custom battle mods are standalone modules.

While Warband doesn't have a native 1v1 "army vs army" multiplayer custom battle mode, players use specific DLCs to fill the gap: Napoleonic Wars DLC

This is the "turn off your brain" mod. Perfect for stress relief or when you want to watch 300 zombies get mowed down by a Gatling gun on a medieval battlefield.

Focuses on improving AI behavior during battles. It adds formations like shield walls and spear walls, and the AI will actively try to outmaneuver or flank you.