NPCs have infinite stamina. Players you need to use blunted weapons. Blunt weapon fittings do not deal stamina damage to player. You need to use truncheons, blunted javelins, or blunted arrows.
the love tap is a legendary truncheon that does massive stamina damage. Use a shield with it to maximize effectz there is a legendary weapon called sword of Crom that eats all your stamina in single swing. Even if you use the reduce stamina fitting. Equip this on a thrall.
Edit: Technically npcs have stamina aka torpor. Using any of them stamina draining weapons I have mentioned above will knock out an npc (animals not included) and you can drag them back to your base with a rope and oput them into a wheel of pain and convert them to be your thrall aka follower/guard