Nah, I disagree. By telling an abuser to pick on someone their own size, you're pointing out that not only would they not do that, but if they did they would get put down. Because people instinctively defend themselves. And picking on someone smaller is the only way to ensure you don't get fought against. It is cowardly. Maybe I'm delusional, but I kind of think that the possibility of the abuser turning on the intervener or otherwise escalating the conflict is not such a bad thing. When done in public, it makes denial of abuse more difficult, alerts the community to their violent tendencies, makes them a social pariah, and may get the police involved. I could be wrong, but just where my thoughts went.