Well, the actual fact is that Southern Baptists, as Christians, claim to be Israel, thus making them part of the community that wrote and compiled the OT and NT.
Regarding LDS scripture, if we stick to the scriptures relevant for this thread – the BoM and the PoGP – it would be false to say that “LDS wrote their scriptures”. The LDS did not write it. Thus, I would argue, any interpretation of the BoM and PoGP that the LDS provides (and any interpretation of the OT and NT that the Southern Baptists provide) must be critically examined. And the prime example of the fallibility of both the LDS and many Protestant interpretations of their scriptures is the unbiblical equation of West Africans with the descendants of Ham and/or Cain.