I don't know if you remember me, but we had exchanged many emails a few years back. I have always remembered your stories of taking your dog out for walks in your stroller
Just out of curiousity, who is ultimately responsible for the hiring/firing of the maintenance man or crew? Does it come down to you or do you have to make a recommendation to your bosses? Also, does your boss have an employment contract with this maintenance team that stipulates the terms of their responsibilities and the conditions in which their contract may be terminated?
Also, have you been documenting each time a unit has not been ready or something has not been done? I would think that this would be important to do from a legal standpoint. Overall, I'm thinking that if there is a contract that you could see it would make your course of action much easier. It could also show your boss that you are on top of things and make you more of a participant rather than someone stuck in the middle.
I hope I haven't rambled too much.