Portuguese Naval history is a fundamental part of the broad enlightment of the art of sailing. They were Pioneers and certainly amongst the firts to venture across the seas in Medieval ages, from America to Africa, India and Asia. In fact they were the first Europeans to come across some iconic cultures ie. Japanese. Many of concepts of sailing depicted in the game were only possible due to their revolutionary progress in the navy field.
having said that, If this game has some hint of historical accuracy, they most certainly, should be part Naval Action set on this period of time.
Oh, and btw Portuguese are not Spanish !