I don't see why Leites should be ahead of either Okami or Maia.
Really you can make an argument for any of them.
Okami's problem is that he lost to Rich, losing to Rich makes people think well Anderson murdered Rich twice so by MMA mat Okami loses this fight(not saying its true). Also Okami isnt very marketable and doesnt really have any exciting or dynamic wins.
Maia has one less win then Thales streak wise in the UFC and really doesnt have that top fighter win to push him to the fore front.
In spite of it being controversial, Thales win over Marquardt is still a W, and Demian doesnt have any W in the UFC yet that really can compare to beating a fighter like Nate.