Campaign has a lot of features that work only in US/England/others formats, like:
Date Personalization (only support Day and Month in english)

Numeric personalization (Currency format) Olny support period as decimal separator (In Latin America we use comma as decimal separator)

Automatic view on line: Include the text "no images, view in browser" only in english.

There are more things than personalization, like Mailing Health that penalties the "crédito" word as ofensive word and many customers are banks and in legal paragraph must to user Credito...