I've been trying to figure out if this is a known bug, but while I've found references to Pyre Zombie issues, everything I see seems to be from before 0.23c .
So, I have patch k, and am playing as the Sheiam. Play Now w/ Normal world size, epic speed, Noble level, defaulted random civs, Shuffle map type, random for the other options.
I make Pyre zombies (also, don't have access to axemen, though I THINK that might be because I haven't reached the proper tech requirements?), but as far as I can tell, they simply act strictly as a 3+1 unit. While they graphically explode on death, they do not damage units in either the tile they are attacking OR attacking from, nor do they damage units in the tile they are defending. They do not damage structures, improvements, nor reduce city defenses.
Which is quite unfortunate, as I am at war with a civilization that I've pushed back to a single city fortified with a TON of archers and warriors, but I can't crack through it because the city has good defenses, surrounded by a river, and I can't get enough units to damage ALL of the defending units to start actually killing any. I'm trying to starve them out, but no matter what I do to stifle the city, it doesn't change the pile of units in it, though the city itself is now low pop and mostly unproductive beyond sea squares that I have no way of blocking yet.
If only those pyre zombies worked, it would be possible to break in.. instead, I have to twiddle my thumbs racking up war costs w/ an enemy that rightfully should be crushed under my heal! Heck, I even burned the forest to the ground! I can't make their life much worse, but can't get the darn thorn out of my side...