User blog comment:Icedeath/A Bleach Rant by me./@comment-1489595-20100506191428

People get too wrapped up in the Espada ranking system. While its true that the Espada represent some of the most powerful Arrancar in Aizen's army its also a fact that politics plays a large part in who gets what number. Remember when Grimmjow pissed off Aizen? Suddenly Luppi was pulled out of nowhere to replace the 6th Espada! Just like that! If Luppi was that strong he could of easily replaced one of the lower ranked Espada on his own initiative. Once Aizen decided he has punished Grimmjow enough he had him healed and replacing Luppi in no time. Politics rather than power decided who was the 6th Espada in this incident.

You can see similar political tensions among the other Espada. Its difficult to say who was really more powerful: Stark or Barragan. But I think it was pretty obvious that Aizen kept Stark as #1 to irritate the ambitious Barragan. It sure wasn't because Stark wanted the position.