Completely disagree.
Page was a much better soloist/lead guitarist than he was at riffing. He only created two or three great riffs ("Whole Lotta Love", "Kashmir", and "In the Evening"... maybe a fourth in "The Ocean"). Iommi crafted at least that many great riffs ("Paranoid", "Iron Man", "War Pigs", "Sabbra Cadabra", and "Heaven and Hell" for starters). Page pisses all over Iommi though, when it comes to solos.
IMO, what made Metallica great was/is the combination of a neo-Iommi in Hetfield with a neo-Page in Hammett.
What's the saying? Opinions are like assholes: Everyone's got one. And it stinks.
So...
Iommi is a riff god, no arguments there. And, like Django Reinhardt, he's only got two good fingers yet is nonetheless a distinctive soloist. And he's probably a Villa fan. But he's not on the poll...
As for Page, there's far more to rhythm guitar than just riffing. He could pull out all the Bert Jansch-inspired English-folksy shit when he wanted to too. In his own way, he's a wonderful guitarist, a tone monster - but he just does way too much tedious blues tock wailing for my taste. Similarly Stevie Ray.
And, IMO of course, Hammet and Hetfield are ordinary guitarists.