In that case I can only suppose that either
a) They weren't paying attention when the War in Heaven and PoS came up in Sunday School, or
b) They were, but somehow went on believing something they'd heard long in the past, without noticing its incompatibility with the WiH and PoS lessons.
I suspect (b) is more likely. If you have believed something for a long time, it is very easy to miss such inconsistencies.
6 one way.... doesn't matter I think we can all agree that the Mormon Church pre-1890 was not very nice, it had issues with outsiders and brown people
if the US government wants to get rid of the Blacks and put down the Mormons they send black settlers that way, hopefully a large number of those settlers are vets of the 54th Massachusetts and other black units of the civil war.