It's hardly that cut-and-dried. As late as 1871, Orson Pratt preached that it was an angel that appeared to Joseph in the first vision, as did John Taylor, Wilford Woodruff, George Albert Smith, and many others. Also, it was Joseph himself who wrote originally that the Angel Nephi appeared and told him about the plates, not Moroni. As with every other church doctrine, these have evolved over time and cannot be attributed solely to the influence of one individual.
I agree. I read a lot about this from Sandra Tanner's books. From what I remember Orson had a lot to do with rewriting the scriptures for the 1871 version and putting together the pearl of great price for the English mission in the 1850's. He had a lot of sway for what mormonism theology would be today. Brigham hated anyone who he thought was competition. Orson wasn't scared of the "old boss."