klaymen: Actually those weaker highest tier units are dirt cheap, can come much faster and come in larger numbers, so it is not outright unbalanced. Also their corresponding heroes (Knight or Barbarian) can buff them significantly with their stats.
True, but an experienced Barbarian with dragons is even nastier :p
klaymen: And lest I forget, on CH forums there is a
balance mod made by UndeadHalfOrc and Darmani.
Seen that, think it changes too much. The main flaw is the AI (at least in battles - always going after ranged units and by HP rather than the actual threat).