I've looked through it, and think that the Un-dead would definitely be my choice of race if I were to play this. Here's why:
Zombies (with one handed weapons) cost 2 points, and have a defense modifier of +2.
Shields cost 1 point and give a +1 defensive bonus.
Heavy Armor costs 2 and gives a +2 to defense.
Zombies with shields, heavy armor, and their complementary one-handed weapons cost 5 points and have a +5 defensive bonus.
That means that it is impossible for a non-orc who is not armed with a bow or two handed weapon to kill an Armor Zombie.
The chance of an orc without a bow or two handed weapon (or a non-orc with a short or long bow or 2 handed weapon) killing an Armor Zombie is one out of thirty-six. Here's proof:
Y=Armor Zombie Remains Intact (it's already dead, so I can't say "lives")
N=Armor Zombie is Destroyed

X 6 7 8 9 10 11 Armor Zombie's Roll
2 Y Y Y Y...Y...Y
3 Y Y Y Y...Y...Y
4 Y Y Y Y...Y...Y
5 Y Y Y Y...Y...Y
6 Y Y Y Y...Y...Y
7 N Y Y Y...Y...Y
^Opponent's Roll
Similarly, someone with a crossbow or an orc with a two handed weapon (or bow) has a 3 out of 36 chance of killing an Armor Zombie.
Only an orc with a crossbow has a decent chance of killing an Armor Zombie: 6 out of 36.
And all that for 5 points! Considering that most enemy missile troops will be elves ( who cost 5 points without a missile weapon), that's pretty cheap.
Also, an army fielding a force of Armor Zombies may want to consider using goblins with long bows and light armor as counter-missile troops and orcs armed with two handed weapons and heavy armor as a sort of strike force for decapitation attacks.
Of course, the Counter-Missile Goblins would cost 8 points each, and the Strike Force Orcs would cost 7 points, so they should be used judiciously. Cause, you know, you can't just throw around 8 point units. They're expensive.
I really wouldn't use humans for anything but as leaders though. But I would use them as leaders. Human Pride!
And if you wanted to exploit the rules to make an unstoppable unit I guess you could spend 11 points on an orc with a crossbow and heavy armor, but that'd be sort of unfair.