OK, typing out loud here. See if this “makes sense”, even a little.
So, the Book of Mormon (“Another Testament of Jesus Christ”) is produced by Joseph Smith. It’s purpose, as noted above, is bait. One is asked to read the Book of Mormon, then the Holy Ghost (Spirit) will reveal the truthfulness of it to you and thereby validating/vetting Joseph Smith. From there the Book of Mormon is no longer a required foundational source as it bears little support to the LDS organization on its own. You have a “vetted prophet” and what he says is the foundational source (D&C, Pearl of Great Price, general church documents).
Without the witness of the Holy Ghost, the logic is circular. As has been argued before, and still, feelings/emotions/etc. are not valid for this determination. How does one know that it was the Holy Ghost and not bad forces, or wishful thinking? Seems if the Holy Ghost was going to get involved it could be a little more direct and not need a throwaway document to bring someone to the LDS organization.
So, now, assuming for a moment that we have vetted everything up to this point, how do you determine succession? We know how they do it today, but that was not in effect when Joseph Smith was killed. There are stories that suggest he wanted to pass the charisma of prophet onto his lineage. So, how is the guy after Joseph Smith vetted? Did Joseph Smith call out Brigham Young? Did he identify rules for succession (i.e., the way it is done today)? Without a vetted source calling out the rules for succession (or naming a name) then how is the new person vetted/validated? (I recognize that we can get more circular logic or at least emotion/feelings as the answer)
This is point of most of the splintering. His wife did not follow the main congregation to Utah. There are stories that other folks tried to usurp the title by claiming divine revelation, and it fooled some, until the individual recanted their story (sorry, don’t have easy access to this anecdote at the moment). So, the majority go to Utah, is that the designation of truthfulness, majority. If it is the simple, then none of them should be Mormon (they aren’t the biggest religion). So, we can deduce that they believe in a church that has a logical and validate-able process of progression of the prophet. How did it pass, authoritatively, to Brigham Young?