This afternoon I spent a little time looking at the difficulty and made a few minor tweaks to some of the basic units.
The zombies are all now all one move speed slower than their living counterpart, but each is 2 strength stronger. The zombies are slow but strong.
I also boosted each of the zombie terrain powers so they the all give +50% strength. So Troll Zombies who are base 20 get +10 in swamps, and Zombie Goblins which are base 8 get +4 etc.
Living Dwarves went from 15 to 16 strong. (Zombie Dwarves now 18)
There were also some minor changes to the spawn rate and movement functions.