Worse than that they staff doctors in name only. The type of quacks who couldn't make it in the real medical world. I really don't understand how they can't be sued for malpractice when they argue a diagnosis with your doctor. At that point they are acting as your doctor.
From personal experience, the vast majority are practicing out of scope. It would cost them a ton of money in overhead to have a cardiologist deny a claim for cardiology related testing or treatment so they just wing it. In some cases it's not even a physician, it's a nurse, NP or PA.
This is where government needs to step and regulate but we all know that isn't going to happen.