I see no problem with dual names as we did for Boden/Lulea.
I like this.
In that case, I'll make it so that names are both near the symbol they correspond to. For Lulea / Boden and Merida / Progreso this could not be possible because there is a single icon (port). Except it is demonstrated that Merida population in the 40s warranted a city (it is 793k inhabitants currently, so it may be)