There's no need to complicate the game with unnecessary upgrades. However, there could actually be more creatures. But that's not the point. First of all, in Heroes 3, the Undead were arguably the strongest race in the late game. At the same time, the other dark factions (Demons and Warlock) also looked quite decent. In Heroes 5, the Undead can't be called weak, but they're not the strongest either, especially considering that other dark factions (Demons, Warlock, and Orcs) clearly suffer in comparison to Elves, Humans, Dwarves, and the Academy. This is clearly an imbalance, and one of the reasons for this is the presence of the Antimagic spell. Also, there's the Battle Fury rune, which I can't seem to accept, as well as heroes like Wingael and Inga, and it's too easy to create a large group of Knights for Humans. All of this shifts the balance in favor of the light factions, which is why people prefer to play as them. But I bought the Heroes games to enjoy some dark strategies, so I haven't been very interested in playing Heroes 5 lately. I think it would be fair if the Undead were the strongest – then the balance would be somewhat equalized.