Eh, I do agree that book 1 needs an overhaul. I'm surprised people haven't made expansions to fix it or add girls or scenes since each book is essentially standalone except oddly enough b4l which does take into account whether you married toph, pregnancy, and whatnot. In B2 slave, the fire nation has a thief as an emperor and a mindbroken azula. I guess Aang did take out Ozai offscreen though but that's a huge change from cucked Emperor Zuko in the comics where he marries Mai. B2 love again just by virtue of Mai not being Empress and Azula being around and either subservient or not is a big change. I don't remember the Earth kingdom episodes from the show to speak about the differences. In either case, Suki was my girl. She had some of the best scenes in the love route and is even part of the foursome with Ty Lee, Katara, and Toph. June wasn't a part of the group sadly.
Funnily enough, in b4 slave route, Tenzin likely has an older brother or sister running around in the Earth Kingdom if you seeded Joo Dee but the game does not acknowledge this.