1. Ariel is a fictional character.
Sorry to break it to you, but mermaids aren’t real. You can’t "miscast" something that is entirely made up in the first place. And if mermaids were real, I promise you they would not have flowing red hair, flawless skin, and bras made of seashells. They would look like those fish that live in deep waters, have sharp teeth, and an antenna that glows. In fact, the original version of the mermaid myth portrayed them as monstrous creatures who lured men to their watery deaths. So, there's that.