You need to be more explicit in your question
They have internal and external schedulers on the same projects.
Different projects have multiple schedulers.
Different schedulers in different regions.
What is the problem your having?
I have not had a problem with a scheduler, so am not able to give insight on that; but have you noticed that in 2015 the shopper fees have gone down? The pay is less than in 2014? I'm in Florida so I don't know if that has anything to do with it.
One scheduler in particular. She does not respond to emails, just likes to schedule shops and disappear. A $15 shop caused me to send 4 emails and several calls to the office to get a reschedule date because the target did not return my inquiry call. The shop was removed from my board, and all the work I had already put into it was almost lost because she did not respond to me. I will not schedule any more shops with her.