I see no issue with it. :)
Hmm. Well, Pietra, if you don't think that your character would team up with a bender and you'd like for her to be last, your character might be left alone for a while! But I'm fine with that, if you are.
Right now, I'm thinking that maybe Malik joins first. Since he's travelling the Earth Kingdom, maybe he could be near the Eastern Air Temple when Sozin's Comet comes. After the attack, my character will be injured and lost, so they could meet and he could help them out. Once he finds out about what happened, and that the boy was the Avatar, he decides to come along and help protect him?
Then, it'd be interesting if Jin and Saili met, with him being a former Fire Nation Soldier and her doing resistance work. Then the two groups could meet up? I'm just tossing around ideas, so y'all feel free to throw your own in!