Homer's a bit of an unusual case. The Illiad was the first written work produced after a long dark age (or close to it; I'm not sure where the consensus is right now on whether Hesiod came earlier), so Homer was drawing on a few centuries of pent-up oral tradition from a culture that had itinerant hostorian-poets. As such, he probably didn't compose all his own verses but could well have been the first to write them down. I'm not sure how effective the technique referred to in the article (stylometry) would be at teasing apart the distinction between composer-of-verse and author-of-lines.
