Sumo Wrestling skill and Knockback –> falling down

[Captain Joy]

Originally Posted by B378

Anyone who suffers knockback must attempt a roll against the highest of DX, Acrobatics, or Judo.… On a failure, he falls down.

I'm surprised the Sumo Wrestling skill isn't listed here as being a go-to skill for keeping your feet after suffering knockback. I would think it would be even more appropriate than Judo skill.

Please explain to me why I'm wrong or right.