You're right, and it's strange that he would make that mistake. One of the miracles of Chanukkah is that G-d gave "the many into the hands of the few." This is very important. According to Greek philosophy (which took account only of the physical and the rational) the few cannot defeat the many. The defeat of the many by the few was a supernatural miracle attesting to the existence of HaShem and unseen, spiritual realities.
Those Maccabee brothers and their daddy were a tough bunch.
Hey, see my Chanukkah tag line!
First, Greek philosophy indeed took account of more than the physical and rational - read the Phaedo.
Secondly, the Greeks certainly knew the few could defeat the many because they had done exactly that at Marathon. A good summary of their views is in The Republic, Book II.