Hi,
Playing a game with the ranger, it took me a while to figure out that left-clicking on an enemy tries to move towards it because it tries to execute a melee attack. And right-clicking tries to execute a ranged attack. Even after I figured out how it worked I kept left-clicking because it felt like that was more natural, until it eventually killed me.
As for how to fix this, I'm not sure. I can see what you're trying to do I think. Maybe other players have ideas.
BTW, thanks for the game! It looks great!