Build Walls and Embankments to funnel enemies into chokepoints. Use Camps or Forts to increase the defense of nearby friendly units.
Prioritize one Barracks (recruitment) and one Smith or Stable (equipment) per city. romance-of-the-three-kingdoms-xi
Ensure at least one officer in a unit has an S or A rank in that unit type (Spear, Pike, Bow, Cavalry) to use powerful tactics. Build Walls and Embankments to funnel enemies into