I don't know the older gens as well, so please pardon possible fail :x
Mermaid: Water-types, especially dragons. Ame-Warshi: Water-types, some flying/water combos. Sakura: Cute, but strong. idk. She'd have a lot of fire-types named "Syaoran". Fuuma: His team would consist of all the pokemon people hate. Like Zubat and Geodude. And annoying-looking ones. He'd also have one badass one, probably a dark-type nicknamed "Kamui". Chitose: Steel and psychic-types. Mechanical-looking ones. Arashi: Fighting-types Himawari: Grass-type (and psychic-type if only because they can teleport away) Hokuto: Cute ones only. And a few weird ones, too. Eevee, Togepi, Oddish, mareep, etc etc. /doesn't know enough pokemon