your criticism seems to come from a definition of war or self defense that comes out of the movies. ie you only fight people when the fight has been announced and you're both on the battle ground in full armor. a) that is not how actual fighting works. b) that is DEFINITELY not how fascists work (in my experience they like to pick the time and have at least twice as many fighters as who they're attacking). c) we are not equal combatants who are fighting for our honor in the sight of god and the king. nor are we going to be claiming self-defense in some court of law that has blinders on and never takes context into account (except when it wants to).
the question of violence, when it is appropriate and when it is just re-creating the system that we're fighting, is maybe a fair one, but that is not the one you bring up (except very tangentially). and to that i would say (again, as i have said many times before) that context and scale are important, and get thrown out the window in these questions, as if we are supposed to be, or want to be, or CAN be, pure.