He'd stop him IMO. Benitez wasn't heavy handed like a Hearns or Trinidad, but he punched with such timing and accuracy/precision that he will absolutely hurt Breland and finish him sometime mid rounds.
I think benitez might have some toruble with Breland physically because he was so tall and rangy and he'd have to respect his power but I think eventually he can counter him with some precise shots and turn things in his favor before stopping him