My ideas for new normal units for the X-Pac would be:
Greeks:
Argonaut: Extra greek hero with a small bonus against mu's but for balance reasons, only 5 can be built at a time.
Mantlet: Mobile shield built from fortress. No attack, and moves slow, but when an archer is garrisoned in it, the archer can shoot from behind the mantlet. the mantlet must be destroyed before the archer can be hurt. note: archers move slower in mantlets, however, so it may not be wise to put every archer in a mantlet
Eggies:
War Chariot: Not a chariot archer, but this would be a melee charioteer with a spear. eats archers for breakfast
High Priest: Melee hero which can pick up relics, but cannot empower, unless under ra
Norse:
Dwarven Berserker: Hero with a ranged attack
Viking: Unit like ulfsark which cannot be built from anywhere except the longboat.