if criminals did things that made sense they likely wouldnt have been criminals in the first place. you'd have to have guards watching these guys who could go off at any given moment. good luck trying to convince real soldiers to trust their lives in the hands of criminals while working together.
Separate units man, duh... and you are so clueless if you think these convicts aren't being beat, raped, instigated, and set up by the people that you trust to keep them in check. The illusion of the neat and orderly prison system, complete with a black and white perspective of what and who is good or bad is total bull ##!#. Some guards are worse that some prisoners. And those are the people you comfortably walk past everyday. It's all an illusion of safety. What's the difference in a guy that rapes another guy at work and a guy that rapes another guy in prison? The difference is the uniform. If you take that prisoner's orange jumpsuit, expunge his crimes, and say, "Go earn your way back into society", when that man comes home YOU and errbody else will think he's a hero because you see him in a different uniform and don't know his past... and because he doesn't have to answer to your negative expectations, he might actually stick to the straight and narrow given a clean slate and all..