No doubt that Clay isn't the same beast, but this is an honest question, not challenging you. To PackAttack's point, Clay was the main guy to block the last few years on the Packers defense, and those defenses were not good.
Were Fackrell's numbers inflated because of Clay's presence? I honestly don't know, I am not an opposing offensive line coach, nor know how many double teams Clay received.
Clay slowed down to your point, I hope the new scenery and being back home works for him. I think complacency plagued this team, offense and defense. And the new front office clearly doesn't have the attachment to some players as the fans. Which may rub people the wrong way, but if they're trying to make a serious run in the next 1-4 years, you can't fall in love with anyone.