Hello! i'm a new player on this site. I want give a my idea.
I spotted that pokemons in the gym, tower and players use all attacks from available. I think that it need change. I have a friend who has water pokemon with grass attacks and he beat other water pokemon in the gym but they can beat him cause they also has a grass and electric attacks.
I think that water poke should has only water attacks, fire poke only fire attacks etc. and the game will be more attractive, because player who want beat a psyhic poke, must search ghost.

That would be limiting the game, the game used to be like that, but more players wanted to use any move they wanted than be limited to types.