It seems more plausible to me that this actually is more like the division of a mind. They often recall meeting each other in dreams (seeing the other alters from their local perspective within the dream). So it seems that the split goes further, and actually gives rise to different experiences within a mind. They live and experience from different perspectives, and start communicating with each other more like distinct minds. In split-brain patients, the left and right hemispheres can disagree on what clothing to wear in the morning, and physically fight over wearing a tie or not.
It seems more plausible to me that associative identity disorder actually is more like the division of a mind. They often recall meeting each other in dreams (seeing the other alters from their local perspective within the dream). So it seems that the split goes further, and actually gives rise to different experiences within a mind. They live and experience from different perspectives, and start communicating with each other more like distinct minds. In split-brain patients, the left and right hemispheres can disagree on what clothing to wear in the morning, and physically fight over wearing a tie or not.