Did aristocratic rank determine command competence?

Were any of the commanders of the different groups of ships competent?

Yes. Jan den Haen, Duquesne, and de Ruyter were capable commanders; the criticism falls particularly on de la Cerda.

Jan den Haen, Duquesne, and de Ruyter were capable commanders. Almeras also appears competent, though that judgment is more tentative. De la Cerda's failure does not establish that aristocratic birth made admirals incompetent. Howard of Effingham's command during the Armada campaign provides a counterexample.