you know what guys , i think we may have the scenario wrong. In pondering, the woman in the tailor shop husband works there also. The son made refereance to "threats". I think "staff" may have been the ones who did the cutting in the underground areas. I dont think they have private bathrooms, those places are filthy. I cant imagine guards, for over a month, not noticing that each AM the boys have somehow gotten filthy!
Besides gruesome murder, i dont know what there skill sets are (and this just be my personal relationship with power tools - not good!) but the cutting is pretty perfect. I dont know how long blades last cutting through steel etc (ie need replacement) .
It has been widely reported that there is consturction going on in there, so "staff" walking around in the crawlways etc with big tools would not be questioned.
I think all they may have done is the cardboard, the dummies, wake up and crawl and run
only my notions