Maybe not a dual-axle Piglet, but I might be able to make an outrunner brushless motor (such as an AXI) with attach points on each side. We'll see how practical it ends up being.
Read the post ANTWEIGHT, BEETLEWEIGHT, AND LIGHTWEIGHT robots. Also, like I said, two of them are too far apart. Besides, using anti-ballast in battle doesn't work. The game hates it.