For a short few minutes I was obsessed with the fact that Ozai could have been good and I produced this (magic!). Um. It's about Ozai and iroh joining Team Avatar, which is made of Hakoda and others, but Iroh is actually bad and spying on them, but Ozai decides to help Team Avatar.
After about a week, it's pretty guaranteed that they're doomed. He's watched everyone in the group, and he's fairly certain that they won't make it - or at least won't win. It's not that they won't try - they're the type to keep trying even when futile - but they're going against a group of people far more skilled than they. Especially if he joins his brother, they won't stand a chance.
Hakoda is a warrior. He's strong, and he's smart. For the most part, he knows what he's doing. He cares very deeply about his family and people - enough to be reckless, at times. This is good, though, as long as he keeps control. He's one of the most reliable people in the group… and he's going to leave. He's not sure even Hakoda knows this yet, but it is very clear. He can see the way he stares at the fire, and talks about home. He can see the way he's stressed about the war - not the Avatar, but the war. The Water Tribe - not to cause offense - need every man they can get, and this is a man who is willing to fight for the cause, even at the expense of others. So he'll leave soon, and that will be the end of their best warrior.
Kya is a healer. It's not to be offensive, because they need her - they need a healer, or at least the avatar does. This war is in one of the… bloodier stages, to say the least, and they need someone who can keep a cool head and carefully lead them when they need it. But she is a child, and she's the one taking the weight of the entire group. It's a big weight - and eventually, it's going to crush her. How will she be able to pick up the avatar when he learns the truth about the remainder of his people? How will she hold the group together when she learns that the one she cares about most in the entire world is leaving? She will try. He knows this, and he knows it's possible that she'll succeed. But that small chance is… small.
The avatar is afraid. It's not a sin to be young, and it's not bad to hope that the war will end soon. He's hoped for that his entire life, and especially with the avatar's return, there's a chance it will. However, that chance will not be fulfilled if the world's last weapon is hoping someone else takes his duties for him so he doesn't have to go to war. It's natural to be scared, and to hope something will pop up so he doesn't have to fight. Yet - if things continue down this road, the war will not end for even longer.
His brother is a spy, and there's absolutely no way that's changing. He's talked to him - carefully, of course - but he's very set in his ways. A spy cannot win the war for the other team.
And then there's him. It's Firelord or die in this country, but that's not this group's focus, so it shouldn't be his, either. He's not quite sure if he's an asset, or if he's hurting the group. He knows a lot about people - he can tell, most of the time, if they're lying or if they're actually going to help them. He can be violent when he needs to be. He knows what war is as well as any of them, and maybe even more. But, he represents all that the Fire Nation means to the rest of the team. He's not kind like his brother, and he can't reel them in like he can. Frankly, he just makes them angry. If they're so mad they can't focus, they can't fight the war they need to.
Thus, the earlier statement. He doesn't want to sound like he has no faith in the team, but… but. They're made of a leaving warrior, a small healer, a scared hero, a spy, and a hindrance. Their chances are low.