Planet of the Spiders - S11-E5
Revealing mistake: When Mike and Sarah are in Mike's car going to the monastery, the car swerves off the road and Mike is replaced by a stunt man.
Revealing mistake: In episode 1 when the Doctor, Ian, Barbara, and Vicky leave the TARDIS, wheels are visible which move the prop around. There is also no back to the prop.
Revealing mistake: In episode 1 when the Doctor is checking the controls you can see the studio lights to the top left corner where the set doesn't completely connect.
Revealing mistake: When the Keeper is on the TARDIS, he asks to borrow the screen. But on the upper left corner, you can see it over where it's meant to be.
Revealing mistake: When K-9 is cutting through the wall of the hut, the cut overtakes his laser at one point.
Invasion of the Dinosaurs - S11-E2
Revealing mistake: When the Brigadier is using a flare to ward off a dinosaur in the tunnel, the smoke instantaneously vanishes as it hits the split screen.
Revealing mistake: Whenever the TARDIS's scanner picture of the Doctor's laboratory is shown, the TARDIS itself is always in the picture.
Revealing mistake: When the resistance are storming the landing bay, one of them punches at least a foot to the right of a guard's face, but he still collapses.
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