Albus nodded thoughtfully. "That is essentially what I was proposing earlier with the Duelling Club, Harry. I am, of course, open to suggestions in this regard, but I feel compelled to caution you against forming a more exclusive organisation amongst yourselves, for two very good reasons.
"In the first place, this club -- however secretive you may think yourselves -- will eventually be discovered and targeted. Practising defence out in the open, under the guise of a larger Duelling Club, will draw less attention to the group, allowing you to hide in plain sight, as it were. At the moment, we have the element of surprise on our side. I have no wish to squander it by arousing more suspicions than simple teaching and learning of defensive magic warrants.
"Secondly, I know the twelve of you are here to perform various well-defined functions and to save specific members of your families or circle of friends. On the other hand, I am certain that many more people will perish in the upcoming war than merely your relations and acquaintances. These people should also be afforded the opportunity to learn to protect themselves. Wouldn't you agree?"