I have viewed and posted a few sets of stats in my time and they really dont tell the whole story. Stats tell the whole picture if the appropriate ones are combined. What we all know is matai has a problem with his timing as far as getting off the line goes. His up and in defence doesn't match our sliding style. While his tackling technique is adequite his problems are with his rushing defence, not his tackling in general.
Travis burns is there because the kid attempts about 5000 tackles a game. Most of the time he bumps off a defender he's usually significantly slowed them down.
As for Orford, he's about 3 feet tall, we can't expect too much in defence condisering most teams will run their big men at the play maker for most the game. As long as he's attacking to the tune of 450 000 a season, slap two forwards either side of him (maybe not king) and ill be happy.