No we didn't do it for performance, we did it for gameplay and it is a performance bonus. We have rage zombies now, they get mad when hit and basically sprint in your face. This is overwhelming to new players and with bread crumbs it felt like the whole city came to my poi and sandwiched me in there. There are still plenty of zombies in the wild, the number and what it does is deceiving. Last night I had 5 snow zombies from across the lake raid my dig quest and I got rekt, no way out. I was in that hole for under a minute and they broke out my frame box and dropped in the hole and I was toast.
Putting it simple, A18 is much harder than 17 "in the wild". There are cougars that pounce on you, coyotes that are fast, vultures etc. Its nasty. So nasty we set the default difficulty to adventurer and the team was still getting raped and it just felt like the biome zombies were this annoying pest that hunted you and there were way too many of them, maybe Shawns voodooo ai code is so nice now that there were always a LOT more zombies than we ever knew there were.
So we turned it down, there are still a lot, and they are pain in the ass, combined with rage speeds and animals, you will thank me for this change. The AI is so much better they hear and investigate to a new player with a fresh look at 18, I should have kept my mouth shut, nobody would have noticed, but instead it would be oh wow I'm surrounded and this is scary af.
So yeah the idea of less zombies sounds bad on the surface. Put simply there are less stupid zombies that can't find you or hear you idling around wasting cpu, but now more zombies (than 17) trying to eat you in your face. How does that sound?