Interesting analysis. We spend a lot of time on this board lamenting 3 pt defense. This blog post by Pomeroy suggests that defense has little control of opponents 3P% in general. http://kenpom.com/blog/index.php/weblog/defense_has_little_control_over_opponents_3p/ (http://kenpom.com/blog/index.php/weblog/defense_has_little_control_over_opponents_3p/)
Now, that said, it doesn't single out specific teams. It might be interesting to see MU's 3P defense percentage relative to a teams average 3P%, both in attempts and in shots made.