Line Assembly Production

For this first method, all you need to do is stack into each doll in the lines, and move them to the line that they should be in. The far left line should have the smallest dolls, then moving from left to right it should be: medium, large, medium, and then small again.
You don't need to fill up the squares, just get at least one of each in each line, with no one in the wrong one and you should complete the challenge.

Gust of Order

Gain control of the bald headed doll dressed in white whose special ability is to fart.
Take him over to the line and use his ability to make every scramble.
Next, stack out and then stack into the doll with the red hair and eye patch.
Use his ability to rearrange the dolls in order and you'll clear the challenge.

Uppercut Shuffle

The final, and most satisfying way of completing this challenge is by stacking into the strong armed doll with the mustache and using his uppercut to attack all of the dolls that are standing in the wrong line.
Upon being hit, the dolls will run back to their appropriate line.