The Borg Queen serves different roles at different times: central processing unit, de facto leader of drones, personality of the Collective, liaison to Voyager, etc. In "Endgame" there is an exchange where the Collective and the Queen are clearly operating as separate entities:
BORG [OC]: Vessel identified: USS Voyager. We will pursue and assimilate.
QUEEN: No. They haven't compromised our security. Let the vessel continue, for now. I'll keep an eye on them.
This leads me to believe that the Borg Queen is not the personification of the Collective as a whole, but a specific personality trait. Since the Collective is a massive gestalt consciousness, then it might follow that its many drives and desires would be so complex as to have minds of their own. Like an individual mind may exhibit self-doubt and other internal conflicts, the Borg think aloud about their possible decisions in extreme circumstances.
Since the Queen program has multiple bodies in multiple locations, then it stands to reason there might an entire suite of programs among the Borg that represent different aspects of its personality. These programs would all be named for positions of peerage: Locutus of Borg, Queen of Borg, Duke of Borg, Marquis of Borg, Baron of Borg, etc. (An analogy would be the anthropomorphic emotions in the Disney movie Inside Out.)
Does this make sense?