Well, you did say (especially Aang).. Which would be impossible because there can't be two avatars at once. And of course it would be better, but they would all be like 80 years old, so not much fight left in them. I mean look at Katara. I'm sure she's going to do something badass in this season, but I don't think having a buch of old ladies help would make it more interesting for kids. For fans, maybe.