What is your opinion about neutral creatures?

What do you think of this unit? It's called a Knight-Goblin. 120 hit points. Magic resistance, stone skin, ignores the first attack.
Not bad, considering that a starting, un-upgraded hero only has 100 hit points.

Yeah - another unit with an unclear purpose! It seems like a level 3 unit, but its abilities are more powerful - probably designed as elite Chaos warriors. And I remembered another one - how was it called - the furious bull from the Haven faction. 300 hit points, immunity to spells, immunity to fear; the only downside is that it can't be controlled because it's imbued with berserker rage, but otherwise, it's very strong!:)