If Olivares is in the same kind of shape he was for Rose but at 122lbs, he'd destroy Barrera. Hell, even if he was in the shape he was for Arguello at 126 he'd beat Barrera. I'm sure he's bitter that deep down, everyone who knows Olivares, knows he's much greater than Barrera.
He was in good shape when he destroyed Efren Torres, and technically that fight was at SBW - Ruben weighed 120. So, if can just use the Torres version, I agree, he beats the crap outta Barrera. Just a far more talented and dynamic fighter.
Olivares is so much more than Barrera... I watched Barrera, Morales, Marquez, and the other guy was Enrique Sanchez, from the start of their careers. They were all very good at what they did, but they were a full level below Olivares, Chavez, Zarate, Saldivar.
Incidentally @George Crowcroft this is Barrera's first US fight. I was there that night; Maldonado was in his corner as his manager.
