Visible crew/equipment: Near the end of episode 3 the inspector is on the plane and just before he goes to look for Captain Blade the camera zooms out and the top of the set is visible.
The Evil of the Daleks - S4-E9
Visible crew/equipment: When the Doctor and Jamie enter the secret room watch the top left corner. A boom mike shadow appears and then moves out of shot.
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