What would change if Zoe was Marinette's twin (instead Chloe's)?
For the sake of this, Mr Lee does not exist.
But as twins, Marinette and Zoe are pretty tight. Both love plants, both delved into creativity, though different types. Zoe really got into theater while Marinette is more of a literal creator and visual artist. It as worked out nicely for Tom and Sabine as Zoe wants to put on shows for them and Marinette would make all the costumes. Present day, Zoe herself doesn't know if she should love that her parents recorded every performance and want to show it off to people, or if she'd rather go down a hole and hide cause it's just so embarrassing she was so bad as a kid.
Playing off the headcanon of Nino being a childhood friend, he actually wound up a lot closer with Zoe instead of Marinette due to both loving film. They may or may not have crushes on each other, present day, Marinette is convinced they do but that's not territory they're ready to cross or name quite yet.
When they come across Chloe, neither of them are all that impressed and Chloe finds she can't get a leg up over either of them. Together they have kept each other's confidence up and have challenged each other enough that they're incredibly cunning.
Chloe has no way to win and neither of them are going to tolerate her bullying the other.
Present day, first day of school, Zoe is going in as a blonde with pink highlights, Marinette's going with her usual style.
Marinette rushes out to save an old man and is hugged and lectured by her twin for it.
Zoe goes to sit with Nino up front.
Mylene sits with Marinette so she can be closer to the other film interested students (and maybe closer to Ivan). Alix in turn sits in the back with her buddy Nathaniel.
Chloe sends Alya to sit behind her with Sabrina so "Adrien" can sit with Chloe. Alya later in the year is able to convince Sabrina to get away from Chloe and the two hit it off bonding over Majestia.
Stoneheart still happens and Zoe and Marinette discover the box together. Marinette is not so interested in being a hero but Zoe is all for it, already got a name (Bugonia), she just needs ideas for her suit.
And so the local heroes are Bugonia and Chat Noir.
And when Adrien comes to class he's in for less ideal time as Chloe's seatmate, expecting him to be her new Sabrina + arm candy.
Also RIP Nino who can't exactly handle one of Paris' new heroes lightly flirting with him when she saves him.
