I see you are shifting the goalposts, from what they plan to do to their reaction to violence when it happens.
The reason they have makeshift weapons is that they don't bring actual weapons. As for who is initiating violence, that's often a matter of escalation, but sometimes violence is a part of the plan for the right-wingers.
From what I could see, Ngo inserted himself into a scuffle that was already happening. I agree what happened was wrong, but it's not like he was hunted down.
Have you seen any of the rest of the iceberg since then? Did the fire-bomber have the assistance of any other antifer?
There will be more violence, because any counter-protester to the alt-right will have violence inflicted upon them.