Continuity mistake: The Doctor somehow manages to secure his scarf across the catwalk, despite having only gone on seconds before the Master. He then manages to put it on again during the seconds it takes for the Master to alter the angle.
Continuity mistake: In "The Deadly Assassin" the Doctor's blood is red but in "State of Decay" his blood is suddenly dark blue. Then it's back to being red in "The Two Doctors."
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