Just curious, you were doing one a month, you hired someone you say you had to train and you bumped up what you were doing to 3 a month, I think you know answer to your own question.
Why would you hire someone you must train and then expect them to do 3 times the work?
You should have hired someone experienced not someone you had to train. Perhaps there is a learning curve for yourself as well in being a manager.
As to resolving this did you attempt to do 3 rehabs at once with the same crew you have been using and now expect them to do 3 times the work? Did you hire someone and not give them the tools to do what you wanted done? Are there multiple crews and some of them are not people you have worked with before? Spend some time analyzing your part in this process.
Perhaps backing off to one a month with your PM to let him or her learn the process and how you want it done, or, if you feel he is learning enough go to two for a few months. To jump up to three is a huge leap and pretty unreasonable unless you had the crews and staging set up for the PM in place.
I am not beating you up I just feel that you need to think things through before making a huge jump.