In addition to the 120 internal consistencies already noted, Moroni 9 includes multiple references of events that took place in Mormon 4-6.
Evidence Central lists the internal consistencies:
How could Joseph Smith manage to do this without referring back to what had already been dictated? How would he manage to do this either side of dictating the Book of Ether which lists out 30 people then includes them into the following storyline in reverse order?
See: