I don't know too much about the specifics of different anarchist tendencies. Do these class war anarchists think in terms of the classes as Marxists do (proletariat, bourgeoisie, etc.)? It seems to me that most of them are primarily concerned with autonomy and authority of bodies over each other, whereas we Marxists are concerned with class divisions, not these vague concepts of "authoritarianism" and whatnot. It certainly has that revolutionary spirit, I will give them that.