Dave and I had this discussion, and our opinions afterward came out
like this - forgive me if I am putting words in anyone's mouth:
A full-fledged resistance system such as has been described would be
too complex.
-however-
A simple "immune to poison" flag is very desirable. The "non-living"
flag should NOT be used as a hack to emulate this effect - it already
has other effects attached to it, and scenario designers may use it for
further things - for example, a magical trap could be scripted such
that any "living" creature that stepped on it would trigger it, and the
scenario could be structured around non-living units being able to pass
this undetected.
There are probably a number of other uses for the non-living flag, and
it should not be understood as a simple alias of "poison immunity,"
which is not currently a discrete effect that can be applied by itself.
Right now, one of the other effects that non-living has is that
non-living units cannot be healed by healing units. A white mage can
heal a friendly necromancer, but he cannot heal a ghost.
Thus, if Darth fool could code in a discrete "immune to poison" flag,
that would be both welcome, and very useful.
- Richard