1 degree (of 360) every 72 years, yeah you could call that slow

Ralph Lyman looks like a pretty good artist! u/Graphenium, did you notice that the SPHINX is included even though it's not a sign or decan? It's there because all true sphinges are not lions but are lion-human hybrids. The famous riddling sphinx is a woman-lion hybrid. That sphinx comes from the abutment of Virgo and Leo! "The idea that the Sphinx’s leonine form was meant to gaze at the constellation Leo on the spring equinox ... had already been worked out in the early 1900s, based on still older astrological claims going back to the Middle Ages that saw the Sphinx as a combination of woman and lion, thus symbolizing Virgo and Leo." This idea goes back to the Greco-Roman era, combining Pliny and others. (The whole blog entry is worthwhile. It also mentions Esneh (Esna), and suggests that it's possible the builders wanted the sphinx to see Leo at the summer solstice instead of vernal equinox, which could give it the traditional dating of 2500 BC; and on the same line it gives an 1822 anon's idea that Seth built the Sphinx in 730 AM, about 3263 BC by my count but earlier by the LXX count. He thinks the earlier dating claim was modified from the later and was influenced by the Dendera Zodiac beginning with Leo.)

The Great Sphinx never had a lion's face that was repurposed; it was a human face from the start (and even repurposing that into another human is sketch). So it wasn't ever a lion but always had a dual nature. The sphinx's pose may be connected to the carved palette of Pharaoh Narmer (who may have been Menes I), a leader of the First Dynasty. It depicts a legless sphinx in a marsh overseen by Horus, a Hierakonopolis version of the Father God. So in Egypt, the original Horus is in charge of polymorphs (there are also cow-women depicted, and Narmer himself wears a bull's tail, making him the world's first furry, and yes I posted it to FurryArt). Sagittarius is a centaur (like Centaurus), and Capricornus is a mer-goat or fish-goat (Hydra is also a hybrid sea creature, probably a serpent-griffin). Another polymorph is visible in Esna next to Virgo, but I don't know who he is.

The Temple of Esna, by Ptolemy III in the 200s BC, is noted for having a complete zodiac, starting with Virgo and ending with Leo. (Obviously the annual order of signs proceeds clockwise but the precession signs proceed counterclockwise.) This is an echo of the likelihood that the zodiac is a complete narrative from Virgo to Leo such that the sphinx became a symbol of the whole narrative.

Conclusion: The zodiac serves as the oldest source of polymorphs such as those seen in Ezekiel 1, and directly informs the first sphinges of Egypt, which have predynastic origin. In time the female sphinx became a summary of the entire zodiac. The Esna Temple suggests that the narrative begins with a virgin seen in heaven and ends with a lion seen in heaven. I know a narrative like that.

New conspiracy theory: Shortly after 1400 BC, Thutmose IV found the Great Sphinx buried in sand up to its shoulders and began excavation. That means Planet of the Apes was really telling us that the (female) Statue of Liberty is the same being as the Sphinx! We were just comparing her to a painting of (androgyne) lucifer, so that boosts both connections.