When I had a client that wanted this type of style, I created precomps of the illustrations that I had traced 3 or 4 times, letting the versions vary slightly. Put one illustration per frame in the precomp. Then create hold keyframes on that precomp in the bigger comp with the timewarp effect set to frame number, to let each version of the illustration be on screen for about 3 frames. Then add a loop expression, and you should have a pretty jittery drawing that you can animate in another comp.
Hope that helps!