Imperial walkers always strike me as a phenomenally bad idea. In The Empire Strikes Back it seems like if one of the speeders had simply slammed into the side of a walker at high speed it would knock it over. Not to mention how easy it is to take the things down with some cable or, in the case of the two-legged walkers, with Lincoln logs.
Making one into a rocking horse is a huge improvement. It's much harder to tip over.