Most of them do, if the skill is functional. Though, Creber Hirelings are not a thing yet. But yes, Agent Hirelings can stun enemies with pistols, Experiment Hirelings terrify enemies with brutal kills, Massive Hirelings grow and get more durable as they level up, etc etc, but many of them have skills that are non-functional on NPCs at the moment unfortunately. I do intend to look into adding functionality for them though.