It ain’t really about who could win in a fight. Will didn’t hop on stage to fight. The point is the situation could have gone a LOT worse if Will slapped someone who would have reacted at all physically.
When Will turned his back and started walking away without so much as glancing over his shoulder, he was wide open. Will could have gotten suckerpunched, tackled, pushed off the stage from behind or worse if he slapped the wrong person.
Would Will put the beats on most comedians in a fight? More than likely. But most brehs ain’t letting you just slap them and walk away with no reaction whatsoever