Joseph Peterson in his most recent carnation of the Heptameron page in esoteric archives has conveniently provided a table referencing standard correspondences of angels to the seven planets. He notes there that Peter D’Abano implied his source for the angelic correspondence was from Averroes (1126-1198) who was a proponent of Aristotelianism and attempted to restore the original ideas of Aristotle. Needless to say although he is in our history books that he was not widely agreed with. As pertinent to the topic of the Heptameron, (and brought to my attention from Dan Schneider) Averroes associated Michael with the Sun but it seemed in his time it was not widely accepted. However the historical Peter D’Abano was fond of his work insomuch as his translation of Ibn Ezra’s work from Hebrew had appended to it the correspondence of the opinion of Averroes which placed Michael to the Sun. This puts the Historical Abano at odds with his contemporary works. But who is going to argue with the authority of Abano? See the first edition print of Abano’s translation here with his noted appended to the end after “hic completus est liber rationem” or “This completed the book”. This indicates the appended opinion to the work is not Ibn Ezra’s but rather Abano’s.
According to Peterson, the compiler of the fourth book was likely Jacques Gohory and since Gohory was acquainted with both the occult publisher Peter Perna and the historical Peter D’Abano (As his texts were prominent in academia through the 16th century), that he wrote as pseudo-Agrippa in the Fourth Book of Occult Philosophy. As pointed out by Schneider, (if not Gohory), the author was likely employed by or attended the first Protestant college (College of Marburg where the 1559 text was also published). Schneider suspects the author being familiar with the stance of Abano likely realigned his historical preference in the work he coined “the Heptameron” (1559) making the first deviation in the established occult world (as well as the source-work, The Elucidarium) and broadcasting it in the massively successful work which changed the correspondences thereafter.
This accounts for why historical Abano and pseudo-Abano are the only references which correlate Michael to the Sun in contemporary writings. This also would account for the apparent sanitation of the Elucidarium as it was modified in the 1559 Heptameron intentionally changing the period perceived connotation of the word demons to angels, “correcting” Michael to the Sun and reordering the work in a more modular and friendly format. It also speaks to the continual modification of the Heptameron in the 1565 edition where even more information was modified. Joseph H Peterson has also vocalized his opinion that Jacques Gohory was also the author of ps.-Paracelsus Archidoxes of Magic, and perhaps also Arbatel.