You and Ramoss have bigger problems than that:
Daniel is mentioned in the Book of Ezekiel>
Ezekiel—a contemporary prophet—believed in a historical Daniel. Ezekiel lived in roughly 575 BC, and he explains that Daniel is a real and historical figure (Ezek. 14:14, 20; 28:3). To deal with this, higher critics have stated that Ezekiel is actually referring to an ancient Canaanite hero from their Pagan mythology. However, Ezekiel places Daniel alongside Noah and Job (Ezek. 14:14) as faithful men. By contrast, Daniel—the son of Aqhat—from Pagan mythology was a Baal worshipper! Why would Ezekiel refer to this man as a hero of faith? In context, Ezekiel 14 denounces paganism and idolatry.
Moreover, even critical scholars date Ezekiel very early. Regarding the dating of Ezekiel, Robert W. Manweiler writes,
“Ezekiel is probably the most carefully dated of all Old Testament books… we here note that the majority of biblical scholars, even of those who reject the inspiration and unity of the Bible, believe most of the book was written in the sixth century BC by the prophet Ezekiel. The prophecy against Tyre in chapter 26 can be dated with great probability at least two centuries before its fulfillment.[1]
Authorship of Daniel | Evidence Unseen
That alone absolutely demolishes your theories.
And may I say also that the only reason you guys late-date Daniel is that you're anti-supernaturalists. You deny the prophetic, and Daniel is so accurate you have to diss prophecy and late-date it to fit in with your world view. But it doesn't work.
