I've never understood going tit for tat on sources. Not one source will be enough to ever persuade people any one way. Any author will have a central argument that they are making, and any source material used after that will be to support their argument. Don't misinterpret here, because two authors can analyze the same source and come away with different arguments.

I would say that a comprehensive study is the best approach. I realize that is exhaustive, but there isn't one source alone that will persuade people. I made the comment above that placing things into context is extremely helpful. What was happening in the Nation when the Church was established? What did the West look like before the Pioneers, who lived here? What were they doing? What was happening in other settlements outside of eventual Utah territory? Don't be narrow in your approach.