Dirk carried a load of sorry s into the NBA finals in 06 and got the best regular season record of the whole league the next season with the same re ed teammates, I think that was what the prime Kobe couldn't do. MJ belongs to a class of his own, and the likes of Duncan and Magic the class right next career-wise, but I don't think there's much difference to tell between Dirk and Kobe, or any player of similar caliber, in terms of greatness.
I agree Dirk had the right support in 11 which was why they won, but it's not like other legends like MJ and Duncan could win championships on their own. MJ was a poor 3pt shooter but the bulls made up for it with Steve Kerr and kuko, and your Duncan also needed not one, but two superstars playing alongside him in order for him to ring. 11' Duncan was just as great as the prime one but he was basically fighting by himself with an injured parker and an ass-sucking manu, which was why they lost.