Easy. Veronica = Rarity (Because of the love of dresses.)

Cass = AJ (Because of the hat and the accent. I know in-game Cass doesn't have one, but I SWEAR to you, in my head she sounds just like Applejack.)

Arcade can be Fluttershy. (Picture him chasing around a bunch of frightened Elvis-impersonators instead of cute animals, and screaming "You're all going to love me!")

And uh... Boone can be Spike. Just because.

Don't judge me.