When a deputy effectively directs a fleet

Can a senior officer be paired with a subordinate who effectively directs the force?

Yes; the carrier commander can exercise practical control because the rest of the fleet must follow and protect the carrier force.

Vian's carrier command under Fraser and Rawlings shows how formal rank and operational direction can diverge. Vian was technically subordinate within the British Pacific Fleet and formally responsible for the carriers rather than the whole formation. In practice, once the carrier force moved, the supporting ships had to follow and protect it. Control of the fleet's central operational asset therefore gave the carrier commander substantial influence over where the wider force went and what it did.