A nitpick, but this is known as ‘neutral’ alignment, rather than ergative alignment. Ergativity is specifically when the transitive subject (‘ergative’ argument) is treated differently to the transitive object/intransitive subject, which are treated the same way (‘absolutive’ argument). By contrast, in the Latin case, all three arguments are treated the same way — hence, ‘neutral’ alignment.

Incidentally, English has a very similar pattern: most animate pronouns have nominative–accusative alignment, while nouns and inanimate pronoun have neutral alignment. It’s pretty common in Indo–European languages.