The team produced less points at even strength when Carle was on the ice. Actually, almost every defenseman saw better production per 60 minutes. That actually lines up nicely with what I saw; namely, that defending Carle was hilariously simple. No goalie worried about his shot...if it even got through without being blocked it was an easy save. So, his biggest threat was the pass. Without Pronger to pass to on the other side that's not much of a threat either. In his last season here teams cut off all but two passing lanes, leaving him with his partner and a winger. Combine that with Lavi not telling him to do anything differently, and towards the end of the year teams knew exactly how to pressure Carle to maximize his liability in the offensive zone.
Seriously, Carle is terribly overrated. He accumulated his points through sheer, bulk ice time. He got ice time because there was simply nobody else to play. Any competent offensive dman who could do more than pass out of his own zone and could be an actual threat in the offensive zone put up better numbers.
On top of that he can't deal with strong competition defensively. We already have a better player in Streit, and TB fans already lament Carle.
As far as the change at even strength, don't forget the coach's complete inability/unwillingness to change his system, the ****show in net affecting the rest of the team, and Briere's implosion leaving us without a 2C are greater factors for the team's decline in offense than losing Carle's one trick. Drop Carle on the team last year and there is little to no change, especially since a big part of the problem with the breakout isn't solved by the dman passing...the team was clumping together along the boards too often and failing to even get through the neutral zone, even if the pass hit them there. Once the dmen made the pass, the turnover was forced at the forward who received it. Carle doesn't fix that...that's something Lavi would have needed to address and he didn't.
People who stare only at point production without looking deeper into his stats or looking at his actual play and the long-term, persistent trends one could easily observe are prone to overrating Carle; meaning, many journalists and fans of other teams. What he actually is, is an above average first pass guy who is either average or below average at the other aspects...including offensive zone and PP play, which are red flags for an offensive dman. He's strictly a complementary guy, and we already had too many of them last season.