A couple of interrelated points regarding Chandler and the Mavs:
1- I think you can make a case that Dallas, at least in theory, made a reasonable move by letting Chandler walk. Why? Their defensive rating ranking didn't change after he left. They remained the 8th best defense in the league.
Why has Dallas slipped? Offense. Their offensive rating has dropped dramatically from last season. And you can see it when you watch the games. There were stretches this year where they really struggled to score. But I think you can make a good case that, had Odom not shit the bed, the offense could have been much better. Personally, for this year's Dallas team, I'd take Odom playing at 2011 level over Chander playing at 2011 or 2012 level, just because of what Dallas really needs. If Odom had been playing at 2011 level, he could have picked up some of the slack for Dirk who is not quite as beastly this year.
2- on that note, given that the Mavs' defensive rating didn't even drop from last year, I question how much of the credit should have gone to Chandler last season. I totally agree that he is a good defensive player, but I'm not sure he was as important as Hollinger suggests. Correlation or causation?