Being a Manager

I have 2 contractors reporting to me.  One of them seems competent, if not exactly personable.  The other one I also thought was competent.  The last few weeks where I have been working directly with him has proved otherwise.  I’ve been validating some of his work (and he some of mine), and I am frankly shocked and appalled at the quality and lack of attention to detail (something very important in our job).  I’m not sure whether it is sloppiness, inattention or sheer incompetence, but to get this work validated has taken much more time and stress than I could ever have anticipated.  It’s just one basic mistake after another, and absolutely no effort to check things after I request to make an update.  Ironically, he is about to take some time off so that he rejoin as an independent contractor rather than through an agency (and hence increase his take-home pay, at what is frankly already a ridiculous and exorbitant hourly rate).  If it was my choice, I wouldn’t bring him back.  But other people seem to have had no (or less) problems with him, and we need the resource regardless.  So it seems I’m stuck with him.  I hate having reports, and these aren’t even full-time employees.