But also, Taunie, girl, find a braincell.
The only time I really found Taunie/Urbain to be "off" was during the whole Rust Syndicate Arc. So they help Philippe in someway, he offers them a crooked loan (which, to be fair to Taunie/Urbain was a really jerk thing for Philippe to do), they come to collect the loan but can't contact them, instead contacts their friends who takes on their interest debt, and then during/after the whole thing just shrugs it off as if they don't have an entire organization of (perceived) thugs after them. Like, the only possibly reason I could see them acting so nonchalant was because they actually knew about the Rust Syndicate's whole "acting like bad guys to force people to do charity work" shtick so knew they were perfectly safe and only would have to start doing charity work when the Rust Syndicate catches up to them.
Honestly, I feel like the Rust Syndicate Arc focused on the wrong member of Team MZ. The DYN4MO Arc gave Naveen a bit of the spotlight, the Fist of Justice Arc brought Emma back for a humorous ramp, SBC Arc once again had Taunie/Urbain as one of the focal characters, and Team Flare Nouveau Arc pushed things along with the plot & Lysandre's involvement. However, there really wasn't anything for Lida, she really got pushed into the background in terms of character arc. And, considering one thing we knew about Lida is that when she first moves to Lumiose City she was struggling with her finances, I feel like it would have made more sense for her to be the one who had taken a loan out from the Rust Syndicate. Being Lida comes with us to the Rust Syndicate (and is the one agrees we'll pay off the interest in a panic after the player calls the Rust Syndicate out), feels like it would have made more sense. Nothing really would have changed storywise, but I think would have shown both how determined Lida was to make it as a dancer and how bad financially she was originally in to take a loan she knew was crooked but at the time didn't feel like she had much of a choice. Also, once the whole issue gets resolved (the final scene of Corbeau giving a "tip" to pay the loan changed to him giving it to Lida instead), it would make the scene of Philippe giving Lida a Water Stone for her Staryu feel a bit more cathartic.
INTERESTING THEORY: I saw an interesting theory concerning Philippe. He mentions he has a daughter, and considering one of his more defining features are his eyes, people think he might be the father to someone who has similar eyes: Shauna. If true, and obviously Lida is Tierno's younger sister, if they went with that Lida angle it would have been an additional connection between the two characters, the father of one of the XY friends first antagonizing and later helping the little sister of another of the XY friends. That would leave Trevor then without a family member representative (well, also the main rival, but let's just assume the player and Taunie/Urbain spiritually replaces them). We know he has an older sister who is living in their family home in Jaune Plaza in XY (aka the plaza that gets replaced with the desert/sandy Wild Area biome), said older sister using the female Ace Trainer overworld model. So unless they pull a surprise like his older sister is Canari, the most of Trevor in ZA is the mention of him going with Sycamore to do research in another region.
FUN FACT: Want to be clever and think you can make enough money to pay off Taunie/Urbain's debt before visiting the Rust Syndicate? It's not hard, in addition to the 100k they were originally given, they accrued an interest of 1 mil. So, what happens if you bring 1.1 mil with you? Does the game up the price they owe? Well... no. What they do is absolutely nothing! That's right, you can have the amount that Corbeau is demanding to be paid, yet you have no option to offer it and still need to do the tasks for the Rust Syndicate. Now I guess the first time playing it's alright as no player would know to do this firsthand, but on replays it does feel like bad writing. If they didn't want to program the game to increase the interest to ignore this issue, they should have made what Team Rust owed something that couldn't be paid off with money. Like maybe the loan is revealed to be part of an on-going contract (so even if you could pay off what is owed, they would only end up owing even more money next payment period as per the conditions of the contract, thus pointless to pay it off; and instead of a money "tip", Corbeau could give them something like a stamp which is needed to close the contract).