Hancock is the sanest of that lot, and has been quite prepared to modify his ideas when new archaeological finds turn up which cannot fit into his original premiss. Not that he's adopted a completely different paradigm.
As I understand it, he's arguing that there's ample time to fit in another civilisation that has risen and fallen, in between the emergence of Cro Magnon man and the Sumerians and the Egyptians.
I'm NOT convinced of this, particularly because he seems to suggest that the Egyptians' technology seemed to appear fully formed out of nowhere. Whereas, it's obvious that they had to follow the usual learning curve.
His ideas about the conventional dating of the Sphinx being wrong seem plausible, though.
At least he's not a loony like Icke who thinks the controlling powers of the world are space lizards in human form. Nor does Hancock quite 'do a Von Daniken' with the Bible, like the other bloke you mentioned.
Hancock seems obsessed with the Giza Sphinx...he claims it to be the 'original' from which all others were modelled during the next three thousand years.
This is patent rubbish; we have a sphinx of Hetepheres I, mother of Khufu, dating to thirty years before Khafre modelled that outcrop of sandstone into sphinx form. There's also a rather damaged sphinx of Djedefre, Khufu's hier. Going further back, there is a base which had to be made for a sphinx found in Saqqara, dating to Khasekhemy, last kimng of the second dynasty. Had this survived, it would have been thirty feet long.
When confronted with this evidence, Hancock stuck his fingers in his ears and ignored it...the same technique he usually uses when dealing with uncomfortable facts.
As for the Giza Sphinx, I'm with Jean Pierre Houdin, probably the foremost living expert on the Giza plateau; the Giza sphinx was simply a lump of rock which got in the way when Khafre constructed his causeway temple; instead of rerouting the temple alignment, he simply sculpted the sphinx, associating himself with the solar cult in the process.
