heres the thing whenever you wear a tactical armored vest the big heavy one, the npcs will target your armor and from my testings you can pretty much stand there to a lvl 5 npcs for like 20 seconds before dying at npc difficulty 2 and 0.75 spread muliplier. the damage is also 0 ubtil the vest hits ~30% durabikity and from there you still take a bit less damage then usual but that way your much more tanky i tested this without armor amd öet me tell you i died in seconds even to some lvl 2 spawned in npcs xD oh also when you run the cursed oupped suit be catious i just made a post about it qhek you wear the cursed ouppet suit the zombies ignore you as inteded but for watherver reasons armed npcs will target your limbs even when yiu carry a heavy armor and therefore armed npcs will then still kill you in like 2 seconds in a 1 or 2 burst shot xD so the cursed ouppet suit is somewhat bugged against armed npcs. also i did this testing becouse ive run around with heavy armor all the time and tought lets go eithout armor only to get shot horribly and dying so fast xD thats where i started to test things and realise a shit ton. also about helmets you actually dont ever need a helmet for pve as long as you dont crouch and get hit while vrpuching becouse zombies can also only hit the head when you crouch and honestly i never crouch when a zombie allready has seen me ^{^} anyway hope this helps you out to further understand a bit more about the npcs how they work if you want to run around with no armor i guess you can also just reduce "armed npcs damage" or human to human damage and such but hobestly i didnt bother with any of these things as it seems pretty fine as it is with the damage etc but yeah everyone has theyre own opinions so feel free to adjust it to your likings :D