More than likely you need to zero out all the face MTs before applying the next one. I had similar results with a face expression pack I got for V3. The expression pose didn't conatin all the zero settings for all the dials, only the dials that were not zero. So I have to run a special zero-all face expression before applying an expression. This is probably what's happening to you. Your face dials are adding together and not being zeroed out. Try making sure they are all zero before applying the next face setup.