I don't know anything about Flynn. Toland's book "Infamy" came out (to the best of my knowledge) in 1982, two years after Prange died.
As I said in a previous posting, I am a retired naval cryptographer. I also have a Ph.D. in ancient history (well, actually, classics, but my dissertation was on a historical subject.) I have always found Prange's work unimpressive. He strikes me as one of what Charles Beard called the "court historians," who told the story that suited the establishment, and thereby advanced his career. Because his aim, like that of the mainstream media, is not to present the truth, when one learns from him, it is despite him. Whereas people like Beard, Toland, Stinnett, and Wilford are primarily interested in the truth.