I disagree with Bauval on most points but there's no reason he can't be generally correct.
It seems quite obvious that the Sphinx faces east to face the rising sun of the equinoxes. The
pyramids are laid out according to the seasons as well. The Egyptians were oriented toward
the south because that's where the sun was. That they developed the calendar proves they
were familiar with the stars and some of this is mentioned in the PT.
There were older structures under G1 and probably G2. There's no reason to believe there
wasn't an older structure at the site of the Sphinx.