1. For the Orc Hero, I would remove the word "mana" from his vocabulary and replace it with "Rage" (= knowledge * coefficient), because ordinary orcs have it, but the hero doesn't. What kind of orc is he then? The hero's Rage affects his direct weapon attack and his war cries. It only appears in battle.
2. For the Orc Hero, common spells on the map are activated by sacrifice: kill your goblin - get a ship, and so on.
Kill goblins - make a boat out of their bodies.
3. Remove the word "mana" from the Shamans and give them the ability to cast spells based on Rage. The more rage, the stronger.
3. Hero duels: if you don't want to destroy your army, fight yourself; if you lose, the result is the same. I don't think it's right to send the hero into the field with the army; let him duel with equal opponents. You can challenge a hero to a duel before the battle and either accept or decline, or during the battle (for example, if the hero makes 5 or more direct attacks on enemy units, he can declare a duel, and you cannot refuse, since he has already entered the field, so you can meet the enemy).
4. Archers can always choose to attack with arrows or in melee. It's strange that there's no melee penalty, but you still shoot until you get close or run out of arrows, or maybe it's better to use a sword right away.
