Bottom line is, Duke is not a really good basketball team right now. They are uber inconsistent - not only game-to-game, but within games.
And, ranking really doesn't matter now. What matters is they start playing well the last half of February and into the ACC tourney. If they do so, they will rise in the rankings.
Duke is generally favored by the committee; but if they want a #2 seed and a real shot at a Final Four appearance, they are going to have to start winning consistently.
One things for sure, just because Duke wins the recruiting war, doesn't mean they'll be a good team with the one-and-done.