What's with the weapon composition? Why short sword with round shield? Long sword with heater shield? And their crossbow unit have pavise shield?
If the mc has bird vision scout, he can easily scouting the enemies movement and hitting them with surprise attack to lower their morale, split their armies, cut their supply lines, corner their armies before big showdown.
The personia army have cavalry on the wing, I think it's bad idea trying to broke the enemy center from the front with cavalry, because the enemy cavalry can surround them easily.