Here is a concept to ponder. What if I got a bunch of my friends and we decided to simply walk into your dojo, take it over and refused to leave and cooperate. I decided that I was now in charge and I was going to run things my way or you would have to fight me and all my friends.
Every class we come back and do the same thing to the point that you no longer can train in the ideals and spirit that you embody in Aikido.
What would you do? Turn the other cheek? Stop coming? call the police? what?
What if I don't care to reason with you at all? What if I and my friends simply want to taunt you and bully you every class? do you yield to us and go find another place to train and let us take over the dojo?
What happens if we decide to follow you there and do the same thing? When do you stand your ground? What do you do from an "aikido philosophical/ethical" construct? How do you resolve this?
The problem with any hypothetical is that it never can ever possibly cover the scope of a real situation. The beauty of take musu aiki is that it spontaneously manifests without technique. There is no answer to your question that would not be based in the same conjecture in which it was pose, and is therefore in the realm of "the map" and not "the territory." Also, to answer the question in a way to satisfy the nature of its asking is to come up with a solution in which the bullies lose and the aikidoka win and get to keep practicing.
Deep in the heart of this question is that longing to win, to overcome, to defeat the "invading bullies." Therefore even to engage in such a discussion is to ignore the principle of the founder described in this quote: "If you think that Budo means to have opponents and enemies and to be strong and defeat them, you are mistaken. The true spirit of the martial arts is to be one with the universe and have no enemies. The essence of the martial arts is the spirit of loving protection of all beings in the universe."
An understanding of this needs to be cultivated. It doesn't necessarily appear to be true to the ordinary way of looking at things, which is why there are many fewer aikidoka in the world than practitioners of admittedly destructive martial arts.
There is no way to prove that moral conviction is the most powerful response to injustice, it has to come to be understood. There are no answers to the posed question until they present themselves at the time when the idea to attack arises in the minds of the "dojo bullies." At that time, at the moment the attack rises so does the solution.