Visible crew/equipment: As the Doctor is watching Will emerge from the priest-hole, look over his shoulder at the far corner. Someone or something appears to be moving in the shadows there.
The Caves of Androzani - S21-E6
Visible crew/equipment: The boom mike is visible at the top of the screen when one of Jek's androids is handing spectrox to the mercenaries. The shadow of the boom pole is also visible on the roof beam.
Answer: In 'The Five Doctors', three separate Cyberleaders are definitely used. So it's likely that Cyberleaders are like unit commanders, of which a fair-sized army might have several.
Daria Sigma