When you apply a "crescent kick", you can:
1. Let your body to pull your leg.
PRO: Your whole body is unified. You can use your body mass to generate maximum power.
CON: Your body move can easily telegraph your intention. If you miss your target, you may over committed.
2. Let your leg to pull your body.
PRO: No telegraph. If you miss the target, it won't affect your own balance.
CON: You may only use your leg power instead of whole body powr.
So which side do you think that you like to be on?