The new warpedia release has provoked some discussion about unit changes for beta 5.  One of the most popular topics is the new mammoth, its 4 wounds and its hefty defense bonus.  This all got me thinking, how can a 4 wound unit be balanced?  What would make a unit an effective late-game city defender?  The answer I came up with is the GOLEM.
So, the golem (or colossus) is a massive humanoid hunk of rock and/or metal, animated by magic.  It doesn't think, it doesn't feel it just acts in accordance with its magical programming.
As far a game stats go, the golem would be a 3-4 turn unit, it would be quite slow (being a lumbering chunk of stone) have decent strength and 4 wounds.  Now comes the kicker, it is MINDLESS, meaning that morale, fear, chaos and command have no effect on it.  So, if it is stacked with a paladin, the paladin's command will not boost the golem's strength.  If it is fighting against a medusa, the medusa's fear will not reduce the golem's strength.
Why is the golem the best answer to my questions?  Well, Beta 4 is chock full of stack bonuses and stack minuses.  A stack with a mid level paladin and a mid level dreadknight is very powerful in itself.  Add in some fear and morale and you have an army that won't take a single loss against fairly strong stacks.
A unit with 4 wounds gets twice the stack bonus of a unit with two wounds (because each wound gets the bonus) so a 4 wounder that can receive stack bonuses will only add fuel to the fire (the fire being overwhelming power stacks).  Therefore, I propose the stoic, relentless, mindless golem.