I like to headcanon that part of the reason Port Puerto is named that is because the pirates were generally more fluent in one language and the aristocrats the other. Maybe it was a running joke at some point to use both words, and then it kinda stuck.
I think that in their world it would be more akin to a very distinct dialect, or maybe just a lingua franca with a large percentage of the same language the aristocrats use. Like to the aristocrats it's *mostly* their language but theres pronunciation differences and a lot of borrowed words/phrases. Maybe when the pescados came into power they had it recognized officially.












