It's been established (not often enough, IMHO) that Spartan's and Wild Dog's guns fire "trank bullets." As for arrows, in real life their impacts are usually nonlethal unless they hit right in the heart or a major artery -- and even in the latter case, they slow the bleeding as long as they stay in the wound (which is why the common practice of TV/movie characters to yank out arrows/spears as soon as possible is insanely stupid). So presumably those henchmen hit by GA's arrows would survive long enough for the EMTs to get to them.
True, there was an arrow shot in last week's episode that appeared to hit its victim right in the chest, but it was probably offset from the heart. As it happens, I just rewatched a Mystery Science Theater 3000 episode featuring an Italian sword-and-sandal flick in which a character who took an arrow hit to virtually the exact same spot in his chest and survived. I was surprised at first, but when I thought about it, I realized it was possible.