Instead of directly throwing the Pokémon's ball as a projectile, the player can aim their crosshair at Pokémon, NPC Trainers or players to target them. A targeted Pokémon/Trainer will be highlighted with an outline to visually communicate that they're currently selected. On releasing the button, the player throws out their Pokémon at the targeted opponent, initiating a battle with them.
This feature would make it easier to target small or fast moving Pokémon, instead of trying to hit them and missing repeatedly. It should probably still be restricted to a certain range limit so it can't be abused over long distances though, communicated by turning the outline red if the target is too far away.
If you want to go all out, it could have an intermediary range that has a chance to hit, depending on distance. Though that might end up more annoying than helpful because you might waste time you could spend getting closer to the target on a miss...