I would have favored Valdez to best GMan as well. I would NOT favor any version of Jackson to beat GMan, who would have always been a nightmare for him.
The feeling is G could be gotten to. I always believed that if he retired or died before the Benn fight that McClellan would never be picked-against in 90% of fights. But AFTER Benn.....the feeling is that you could almost authentically pick Stanley Ketchel or Bugs McLugs to "wear him down in a war"