Anarchists have proven thousands of time since it was written that they are very willing to use force against capitalists and fascists but biting the hand that beats you in itself is not an authoritarian act.
Ok I can agree there but about counter revolutionaries after the revolution? Do you let them organize and gather support in the name of free expression? Do you engage them only after they start shooting at you?
Another question I have is how do you handle defense of the revolution from outside forces? Sure you could have militias with elected officers and whatnot, but what if part of your anarchist territory does not want to fight to defend the revolution? I could imagine the people further away from the frontlines would be less inclined to go and fight and I'd also imagine drafting people would be too authoritarian for anarchists.