IMO, non-jacket wrestling is more complex.
For example,
With jacket, you can do foot sweep by holding on your opponent's sleeve and upper collar.
Without jacket, you have to train:
- Upper arm push. shoulder pull sweep.
- Neck wiping sweep.
- Elbow locking sweep.
- Palm lift upper arm sweep.
- Eyebrow wiping sweep.
- ...
Without the wrestling jacket, you have to find many different contact points. This make the throwing art more complicate.
One should learn both:
- Winter time ski slope SD skill, and
- Summer time sand beach SD skill.