It's better than not having them there at all. The other NPC's that "do" go to restricted areas were(....for me)always weaker than a gelded NPC that I had to force to go. Plus they continue to get experience in those areas, making them even stronger when they get out.This was a weak spot in the game as far as I was concerned, if they didn't want you to use the NPC's they should probably should have made them go unconscious or something the whole time(or maybe flee after a set time)....and no getting experience.
-Karst (Loyal Order of Diaper)