Shedding in pieces, as long as it all comes off, is fine. If it doesn't then I would suggest a humid hide. They're great. Now it sounds like you may have a couple other issues that I think you need to address. The first being housing two snakes together. I would separate them. They are not social animals, and really do not need the added stress. Secondly I agree with new2bp, get those temps up. Around 82 on the cool side and 92 hot side. Fiddle with undertank heaters and heat lamps if you have to but definitely get those temps up. How are you checking temps and humidity?