I think you are putting too much weight on Pochan's Grand Gallery ancestors idea.
Based on Egyptology, the number of King's ruling Egypt from Narner 1 dyn. to Khufu 4 dyn. is 20. Therefore the 27 ancestors ideas does not seem to make sence. This especially if we notice:
Moon orbital period = 27.321661 days
Porphyry, Life of Pythagoras , from:
17. Going to Crete, Pythagoras besought initiation from the priests of Morgos, one of the Idaean Dactyli, by whom he was purified with the meteoritic thunder-stone. In the morning he lay stretched upon his face by the seaside; at night, he lay beside a river, crowned with a black lamb's woolen wreath. Descending into the Idaean cave, wrapped in black wool, he stayed there twenty-seven days, according to custom; he sacrificed to Zeus, and saw the throne which there is yearly made for him. On Zeus's tomb, Pythagoras inscribed an epigram, "Pythagoras to Zeus," which begins: "Zeus deceased here lies, whom men call Jove."