The biggest weakness in EWOM is that a winning strategy is - build one big army and march throughout the world to crush the AI. No need to complete quests or engage in diplomacy. Just march and crush the AI.
This makes for a really boring game against an AI that sends out unguarded pioneers (settlers in Civ Terms), never builds archer units or catapults (in Civ 3 the AI builds catapults, archers, tanks, etc), waits to attack until the human army is so strong that it can't be beat, never uses magic in battle and sends out small armies that are sure to be defeated in battle.
In EWOM I find that I can "easily" dominate the world with any of three strategies;
1. Archer based armies that decimate the enemy before they can close with my archers.
2. Melee based armies supported by a magic using sovereign and champion. By the time the enemy reaches my units they are so weak that a single attack crushes them.
3. Army of Champions in Magical Forged Armor wielding Magical Swords that strike down their opponents.
In my opinion, the one improvement that would most improve EWOM is enhancing the AI so that some sovereigns will field an army that challenges you with an army with archers, catapults, magic casting champions, summoned creatures and champions equipped with magical armor and weapons.
