That has been my experience as well.I have found these also can come under the influence of a 'chasmatic-cult like' leader due to the lack of proper oversight.
In the ones I have participated in.......when those leaders were corrected for what they were saying by the words of Scripture, then began the "contest" of who is right. It was always.......
"Well, God has spoken to me and I believe what He said to ME".