Let's see if we have this right. Rittenhouse runs away from the attackers, that looks a lot like retreat to me. Rittenhouse, when retreat was no longer an option, raised his weapon and pointed it at one of the attackers. That, to me, would serve as a very clear notice that if I don't stop, turn away, or otherwise reduce the threat that I pose, I will in rather short order be ventilated. What else is required?
According to testimony, Rosenbaum, instead of doing the smart thing and at least trying to get away like the smarter Rittenhouse, tried to attack and take away the gun. How stupid do you have to be?