100,000 BC - S1-E1
Revealing mistake: Susan is supposed to be running through a forest. It is painfully obvious that, in fact, she is simply running on the spot against a back-projected film, and the branches that hit her are simply studio stagehands, hiding just out of shot, hitting the actress with twigs.
The Daleks - S1-E2
Revealing mistake: In episode one, when Ian notices the breeze, a wide shot of the forest shows the background dropcloth is moving. (00:02:10)
The Daleks - S1-E2
Revealing mistake: The Dalek that Ian hides from in Episode Seven has a bad castor. The flopping of one of its wheels is audible. (00:08:20)
The Daleks - S1-E2
Revealing mistake: In episode six, Ian helps Barbara get a grip on the rock and a piece of the polystyrene pops off in his hand.
The Daleks - S1-E2
Revealing mistake: The supposedly heavy statue Ian drops down the lift to destroy the pursuing Dalek in episode four wobbles when he first touches it.
The Daleks - S1-E2
Revealing mistake: Toward the end of episode two, when Susan opens the TARDIS doors, the console wobbles.
The Daleks - S1-E2
Revealing mistake: In the Dalek city, it is unfortunately obvious that the "tunnels" behind the actors are just photographic blow-ups, as you can see the bottom of the wall meeting with the floor.
The Daleks - S1-E2
Revealing mistake: There are numerous scenes where the background Daleks are blown-up photographs. The most obvious is in episode five when The Daleks are discussing the radiation drugs.
The Daleks - S1-E2
Revealing mistake: When the Thals are using sunlight to blind the Dalek cameras in Episode Six, wide shots of the Dalek city show it moving back and forth from bad matte combination.
Revealing mistake: You can see the studio floor in the "white void" outside the TARDIS door in early shots during episode one of this story.
Revealing mistake: In episode one, the Voord that falls down the pyramid shaft is very obviously a cardboard cutout.
The Aztecs - S1-E6
Revealing mistake: In the final fight, Ixta sends Ian staggering into the altar, which slides out of position across the floor. Also, at one point the edge of the raised set they're fighting on is visible briefly.
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