I believe this will open a completely new tactical option; weapons which are meant to not puppetteer enemies, but turn them relatively docile (by changing faction to civilian in case of Mind Control). On the upside, such 'confusing' weapons can be much stronger/faster/cheaper to use than their Mind Control (change to own faction) counterparts.
Example: Herder's Staff in XPZ. My idea for it was to be a pacifying weapon, but I went for MC since it was the closest approximation. Now if it could change enemies into temporary civilians I could give it more attacks per turn, and this gives a fresh dimension to psionic combat: mass confusion instead of direct puppeteering.
As for zombify I don't have any concrete plans yet, but it certainly could offer access to zombifying weapons to player - a new dimension as well.