2 legs on 1 side and 1 leg on the other. And no, 1 motor can move all 3 at different speeds, even different directions though in repeated patterns. One axle can turn 3 cams, no problem.
I saw a video on a toy, IIRC the Furby, and how little it took to drive the animation. The Big Secret was that the inventor is a whiz with light mechanics as well as electronics.
Robin, you do model trains and layouts. Have you ever used a wire jig to make movement pieces? This would be with steel wire, not jumper wires. 