While I somewhat agree, Belfast is a special case. Those guys have a long history of paramilitarism and organized violence. Both the Irish Catholics and the Protestant Ulstermen. They aren't starting from effectively zero. They went out in pure black, nearly always totally masked up, beat up people with phones, made threats to people to turn off their Ring cams, and hit migrant targets quickly.
The other protests in the UK leading up to this were sloppy messes with near to no opsec in comparison. Drunk dudes with their faces 100% in the open, phones recording them everywhere, shouting "TOMMY TOMMY TOMMY" and preferring to throw wheelie bins at the police rather than hit migrants where it hurts.
Edit: oh and they had lists of addresses to hit compiled and spread around. Every single nationalist organisation in the west needs to copy these dudes as closely as possible from now on or be rendered irrelevant.