It is probable that Manuel Arbo was not as well known to Spanish-speaking audiences than the majority of actors and actresses who appeared in "Eran Trece." Please note how much screen time Raul Roulien, who played Max Minchin, receives, especially during the party scene aboard ship. Also, Charlie Chan, who appears at about the middle of the movie, was probably considered as something of a secondary character by those involved in this film production. One more thought, if I may, is that by listing the Charlie Chan character last, he still received some prominance in that he was not "lost" in the middle of all of the other listed characters.
While Manuel Arbo may not have been very well known to Spanish-speaking audiences of the time, the opposite was true for Warner Oland who was top-billed in "Charlie Chan Carries On," the "sister" picture to "Eran Trece." Indeed, the latter was chosen due to his audience appeal for having successfully protrayed Asian (Chinese) characters in the past.
