Hi Mark,

With respect to Step 10, you may find the following papers by Joanne Conman of interest. The first, published in 2003 proposes to set aside Neugebauer and Parker's proposals for a model of the Egyptian Decan stars and proposes a new model consistent with the descriptions of how the decans operate from the Carlsberg Papyrus. The second paper builds upon this model to demonstrate the planetary hypsomata (or places of exhaltation) from astrology were, in large part derived from the Egyptian Decans.
Conman goes on to propose
"Because of Neugebauer's erroneous theory, Neugebauer and Parker failed to recognize the decan system's assimilation directly into Hellenistic astrology."
"The Greek astrological signs, first attested in the fifth century BCE,7 are twelve 30 degree divisions of the 360 degree circle of the ecliptic spaced out over a 365.25-day year. The thirty-six 10 degree divisions of the ancient Egyptian decan zodiac were easily incorporated into the Greek zodiac by allocating three decans to each sign."

Joanne Conman, It's about Time: Ancient Egyptian Cosmology, Studien zur Altägyptischen Kultur , 2003, Bd. 31 (2003), pp. 33-71, accessed from [www.jstor.org]
Joanne Conman, The Egyptian Origins of Planetary Hypsomata, Discussions in Egyptology 64 (2006-2009)

Regards,
Brendan