Actually, I get the impression that the book does intend to say that--otherwise, why would they give me the exact square mileage that can be protected by one dragon? They just seem to have left out the detail of how many total dragons should be at the PCs' disposal.What I don't think the book intends is for you to say "Nymmurh has 23 bronze dragons behind him, so how would you like to assign those dragons?"