Short Form
Last of the Meheecans- Domon Kasshu (Mobile Fighter G Gundam), Professor Layton (Eponymous), Carmen Sandiego (Eponymous) and Miriel (Fire Emblem: Awakening) VS Luca Blight (Suikoden II), Lilianne Valendorf (Mana Khemia 2: Fall of Alchemy), Bowser (Mario Series), and Athena Cykes (Phoenix Wright Ace Attorney: Dual Destinies)
The invaders need to all get across in order to win, which means that the best way for them all to get across is to pool their resources and work together in order to avoid letting the other team pick their weakest member and making sure that one person doesn't get across. However, they hit a bad start when their three alpha personalities, Luca, Bowser, and Lily start to clash, hard. And as skilled as Athena might be at psychology, even she can't make these three work together, which means that there's going to be three separate teams trying to make their way through, with Athena likely trying to help Bowser on the idea that Luca simply won't listen to her (he's notoriously disdainful of advisors/strategists), and Lily already has Whim to help her out.
Against this trio there will be a fiendish maze laid out by Professor Layton with help from Miriel. Let's be honest here, the guy has mini-games in all of his games except the first one where he has to set up convoluted pathways for others to follow. One of them is literally forcing a poor rodent to scurry along a path of his making through clever uses of carrots and sticks. Against intellects the like of Lily, Bowser, and Luca.
Luca will actually be fine because sooner or later he's just going to snap and start breaking the maze. However, this being easily anticipated, no two entrances will lead to the same section of maze, so it's unlikely he'll open a path for anyone else. Meanwhile, Carmen Sandiago will use her thieving skills as a scout, picking out the team that's looking the most vulnerable, and then leading them into an ambush where Domon will get the drop on them and remove them from consideration. Since Domon can, even without his Gundam, take out mook mechs and skyscrapers, either Lily or Bowser will prove easy prey for him without any backup. So, as it stands, Luca gets through, but like as not, none of the rest do. Which means a victory for team defenders.