Fundamental(ist) Difference

So I've read in the news lately that just as the LDS church has put out statements to establish the difference between the LDS church and the FLDS church, the FLDS church has also put out statements to emphasize the similarities of the two denominations. My feelings on this topic are mixed. While I know that they claim to believe the Book of Mormon and modern revelation and such, it bugs me because obviously if they had believed those things they would have understood the path by which revelation comes (that being through the Prophet, quorum of the Twelve Apostles, Stake Presidents, etc.) and believed that the Lord works through his Twelve Apostles and their breakaway sect wouldn't even exist.
I don't really get it. They disagree with the church leaders and apostatize. They determine the will of the Lord for themselves and create their own prophet. Then they go back and say, "Hey look, we've got so much in common with these people who we left." I guess all I know is that the Lord knows all things and will guide us where we ought to be. He will never lead us astray. If we follow we're blessed. If not, then we're on dangerous ground.