There is no simple answer to this question. In my experience most parish churches do not place a great emphasis on venerating ALL the saints everyday. What I mean is that Serbs are primarily going to remember Sveti Nikola, Sava, Simeon the Myrhh-gusher, and Tsar-Martyr Lazar/Kosovo Polje before Isidore of Seville if they even know who he is but parish churches are average people.
In terms of the Church ALL Spanish Saints you listed are venerated. Before Fr.Seraphim (Rose) died he was working on a book about the Orthodox Saints of Spain but unfortunately did not have the time to finish it. It would be better if there was more knowledge and appreciation of the Western Saints among Eastern Orthodox. Still I confess I seldom do more than read the names of most of the Saints listed everyday for commemoration.