Are you criticizing Gueranger, or the Breviary?
Are you Catholic?
I recently read several history books about the period. One about the Norman conquest, another about British history generally from the Romans to the Tudors. Also, have read Churchill’s Birth of Britain. I like to sift through lots of sources. The Confessor was romanticized at some point, but it seems that the truth about him is not so prosaic. Having been a student in the past of the Soviet Union, this description of him reminded me of nothing so much as a biography of Stalin written by the Kremlin. It was just so over the top.
I am not criticizing anyone. They are products of their time. But this kind of writing is how history becomes myth, and then the truth is obscured.