: I believe Guardians are unmanned save for the Promethean automated combat
: forms and vehicles stored aboard. The vessels seen at the Apex were
: intended by the Covenant to be used against Humanity by the Prophet of
: Regret. Presumably these ships, which I believe were designated as
: dreadnaughts, were intended to be crewed by Covenant troops rather than
: coordinating Forerunner ancilla of varying mental capacity and
: personalities.

It also doesn't make much sense for them to be Guardians, as they weren't deployed to any planets.