Larian Studios Forums Divinity: Original Sin 2 Divinity - Original Sin 2 - General What's the use of sneaking/guerilla in combat?

Well you can go back into sneak during a fight.
Also once the combat starts you can select your character who is in sneak and not part of the fight. Position him in real time while the combat is frozen and get a free backstab.

All that being said, I will point out that if your character does enter the combat later, he will not be part of the initiative track until the next round which can mess you up and feel unsatisfying.