NPC’s can spawn underground in evac shelters.
I once had 3 or 4 NPC’s huddled in a corner and didn’t dare attack them cos they had shotguns and uzi’s.
I manhandled them later on with krav maga or something and disarmed them on by one and may have blasted one or two with a shotgun point blank range.
Manhacks are easy to kill, just throw shit at them.