So would the trainers themselves be playable with their pokemon'so moves, or would they have a team and the pokemon are playable? The latter would be better imo. A 3 on 3 fighting game with each of the 3 pokemon on a team having different abilities and fighting styles.
For Kanto:
>Brock: Onix, Graveler, Kabutops
>Misty: Starmie, Vaporeon, Poliwrath
>Surge: Raichu, Electrode, Electabuzz
>Erika: Vileplume, Tangela, Victreebel
>Koga: Weezing, Golbat, Muk
>Sabrina: Alakazam, Mr Mime, Slowbro
>Blaine: Rapidash, Magmar, Ninetales
>Giavonni: Rhydon, Dugtrio, Marowak
>Lorelei: Lapras, Jynx, Cloyster
>Bruno: Machamp, Hitmonlee, Hitmonchan
>Agatha: Gengar, Haunter, Arbok
>Lance: Dragonite, Dragonair, Aerodactyl
>Blue: Gyarados, Exeggutor, Arcanine
Oak: Venusaur, Charizard, Blastoise
And you would start off with Pikachu and the other starters, and gain more Pokemon to build your ideal 3-man team.