Aketxe lacks chemistry and an understanding of how his role meshes with the rest of the team, which is purely a result of lack of time. The qualities he's shown in his limited minutes are at a significantly higher level than Chapman or Hasler. He just doesn't have the benefit of familiarity that the other players have.
FWIW I remember around this time last year someone saying Vazquez is "certainly no better than Osorio"