Alright, this time I did quite a run into your mod.
And I have to say, undead are broken.
This time it was 3 years into the game and near 100 fort population.
Large militia of 35 dwarves, all are reasonably experienced and well equipped - multiple layers of padded-leather-bone armor, 4 to 7 point skills, one hammerer veteran of skill 9, and most importantly - everyone is equipped with steel (hammers/maces were bronze) weapons of mostly exceptional/masterwork quality: half the men with spears, the other half - axes, maces, hammers and one swordsman. 5 marksdwarves.
Then one winter the undead siege comes. And look - it is only 2 enemies, a duo of elite human crossbowman doomed ghouls. Alright, I think, they are probably strong, but my boys are well trained and well armed, I can handle this.
Then the massacre ensues. Those doomed ghouls were disarmed pretty quickly, before any casualties on my side, but then they proceeded to slaughter my militia.. with foot kicks.. They were literally just jumping around kicking and jamming hearts through ribs, slowly but steadily. Absolutely no wound could stop them - broken legs, smashed arms, even fractured spines and neck cloven asunder - nope, they just went on and beat everyone 2 vs 35.
My guess is that it's a combination of vanilla buff to undead with the changes in your mod that strengthened them even further.
Now, I like the scarcity of metals you introduced, the variety of weapons, archer sidearms - great idea. I can't play vanilla after this, but the undead seem to be utterly unbeatable. No major mistakes were made on my part, I was well prepared, yet my steel armed militia was utterly deleted by 2 human sized entities that wouldn't go down no matter the damage done to them.
I don't know. Are these enemies unkillable and supposed to be cheesed out with traps and the like? If that's so then it's no fun at all.
Seriously, I enjoy hardcore challenge, I accept taking losses, I love the dramatic effect of it all, but being deleted in an unfair way is very disappointing.