In the past couple of years (especially as I dip my toes into the occasional roster-building), I've come to really enjoy looking at fictional characters and wondering how they'd work in a fighting game, in a more traditional "break this character down to a key unique style and go from there" kinda way. It's weirdly made me more appreciative of media (like kids shows) that on a surface level can feel kinda samey.
Like going to the idea of a general PBS kids show crossover again, how do you differentiate all the copious amount of "cute animal protagonists" or "confident slice-of-life girls" without all of them just being generically good guys with generic good guy movesets & traits? It's simple; just look closely at their unique traits of both the characters and the general tones of the shows themselves, and nail down base concepts, something that can be easily conveyed. Molly could be "Alaska Native Vlogger", emphasizing both her culture and some modern flair in the moveset, with your obvious "cold attacks" on top of that, while Alma could be a "Bronx Beatdown Artist", having a tougher Bronx flair and some stylish dance moves, a more rushdown type perhaps. Or you could go in completely different directions with either of them depending on the context, but you can still find ways to differentiate any grouping of characters.