I feel that current weapons and tools of war from CDDA reflect reality - that being, weapons of modern warfare evolved from fighting with and against guns, tank, aircrafts and so on.
So why shouldn’t humanity create the best and cheapest anti-zombie weapon - melee, no anti-armor, Anti electric shock and acid.(strangely enough I do not see grenade zombies a lot of late so they will be ignored)
Not even asking much. I think Mechanics are able to create heavy, noisy, pilotable, 4 meter tall metal box + as much circular saw/spinning blades pointing outwards + thickest armour you can scrap off from metal objects on tracks + copper grounding and acid-proofing key parts. Maybe Arms if you are into that.