en.wikipedia.org/wiki/Ergative%E2%80%93absolutive_alignment

This sentence conflates ergative alignment in general with syntactic ergativity.

Authoritative sources distinguish these two things:

• Dixon’s Ergativity explains that a language has an S/O pivot only when its syntactic constraints treat S and O alike and A differently; such a language is then called syntactically ergative.
• The same source also states that many languages with morphological ergativity are entirely accusative (S/A pivot) at the syntactic level.

So an ergative language is not simply “said to operate with S/O syntactic pivot.” That is true only for the subset of ergative languages that are syntactically ergative. Many ergative languages have ergative case/agreement morphology but do not use an S/O pivot in syntax.

This overgeneralizes from the particular example nouns dominus and servus.

Latin nouns belong to multiple declensions and take different nominative and accusative endings depending on declension, gender, and number. For example:

• first-declension nouns have nominative singular -a and accusative singular -am;
• second-declension masculine nouns often have nominative singular -us and accusative singular -um;
• third-declension nouns have various nominative forms and often accusative singular -em (while neuters have nominative = accusative).

So it is incorrect to say that Latin subjects are marked with -us and objects are always marked with -um. Those are only the endings used by some second-declension nouns, including the specific examples shown here.

The phrase is inaccurate in two related ways.

1. In Georgian linguistics, a screeve is not the same thing as an aspect. A screeve is a verbal paradigm combining tense, aspect, and mood information.
2. The aorist is one screeve (within the aorist series), while perfective is an aspect value that also appears elsewhere in the Georgian system. For example, the Surrey Morphology Group’s overview lists both the Future and the Aorist as perfective screeves. So the aorist screeve is not simply “another name” for the perfective aspect.

Because of this, saying that Georgian ergative marking occurs only in “the perfective aspect (also known as the ‘aorist screeve’)” is misleading. A more accurate description is that Georgian split ergativity is tied to the aorist series/screeves, not to perfective aspect in general.