Someone asked me a question, so I figured I would answer it here.
The question was basically, why did I set Lucian Cold Iron to be at level 5 and get the plague promo.
It is simple really, I agree with Kael about Lucian being overpowered if given the Hero Promo early. But I feel that if he can survive to level 5, he should get a chance to be a "real" hero unit. The Plague promo forces the aggressive player to slow down his use if they reach level five by just harvesting barbarians (he will only be able to heal in his culture) and if they are at the point they can get a priest to heal him, then he shouldn't be overpowered. Granted the pool of tears can heal him outright, but this is a bonus/reward of finding this wilderness wonder IMHO.
Over all he isn't much stronger than the base Lucian. A good mage can rust his Iron promo and dispel his enchantment promo. His additional Ice damage (+2) is the gift of his weapon and is permanent. It will take some time to regain his experience, but the hero promo will make it automatic.