Jackson wasn't just powerful he was very fast and had short crisp punches inside. I think he'd pull the trigger too quick for Duran. Moore and Barkley shouldn't be mentioned in the same sentence as Jackson.
Yeah, Jackson's boxing skills are getting underrated. At his best he could really put nice punches together. McCallum also stated that he had virtually no tells, which is hardly something you can say about Barkley. At the time of the McClellan fight he had declined to be more of a stereotypical puncher, but at his peak he was tremendously dangerous. Duran had trouble with fighters with fast and sharp punching after he passed 30 and his reflexes slowed a bit (who wouldn't). Add Jackson's insane power to that... Either Duran boxes cautiously to a points loss or he gets stopped.