I don’t disagree with anything you’ve posted. I just finished Massacre at Mountain Meadows by Walker, Turley, and Leonard. Previously I had read Will Bagley’s Blood of the Prophets. The information in these books isn’t easy on the Mormons, even though the Walker book is by Mormons. The interesting thing about their book is the extensive use of primary sources (first-hand accounts). It was published by Oxford press and peer-reviewed before publication.
About 140 pages of the 380 pages in the book are dedicated to notes, citations, and sources. I thought it was an interesting read and seemed to document and present its sources as precisely as possible. It’s much better than accounts written by family members 150 years after the incident, in my opinion.
The links I provided contained the actual 1859 investigation report, and the accounts from surviving children who remembered the massacre.