Why aren't undead immune to poison?

[Karlos]

I've been having this and similar thougths over last several years of playing KB games. But now, with the undead onslaught, it was rattling in my head all the time.

All undead should be immune to poison, except the necromancers. You shouldn't be able to affect ghosts in any way, except by magic or astral damage (so no poison, fire, frost, melee or projectile damage).

Flying creatures shouldn't be affected by the giant's jump. Machines should be completely immune to poison damage too, as well as more resistant to physical and fire dmg. Cyclops should have like 70 phys resist. Basically all creatures' resistances should be much higher in order to make more sense (ent to physical, polar bears and most vikings to frost, plants to poison, fairies to magic etc.) And I'm sure there are other possibilities.