Bucannon is not Craig Dahl. I know that you're getting that report from CBSSports, but they're doing him a great disservice by comparing him to Dahl. Dahl never had the ballskills that Bucannon has, and will never have them. Dahl has never had the coverage skills that Bucannon has consistently displayed throughout his career. And while Bucannon does have problems with tackling, it's not because of an unwillingness on his part. His problems can be fixed.
Better comparison is a lesser version of Eric Berry. Not as highly regarded and has flaws, but he's just as dynamic a playmaker if you give him a shot.
Also, when I mean a lesser version of Sean Taylor for T.J. McDonald, I don't think he's going to be as good as Taylor was. Taylor would probably still be playing at a high level were it not for his untimely death. T.J. Mac has a long way to go before he's at the level of Taylor.