Polylang and template files

One option is to create a single category.php file with conditionals. So, you would have something like this:

<?php
if(is_category('one') || is_category('un') {
// your code here
} elseif(is_category('two') || is_category('deux') {
// your code here
}
?>

This way you can still output different code per category, but you won’t have to copy category-one.php to category-un.php etc.