It might not be meant to be arrogant, and Rowena can recognise that, but absolute power and certainty often sounds arrogant regardless. She's known enough powerful beings to know that.

"Magic isn't similar. There are many sources of magic, and even those who are not witches can use it."

In her world, anyway. Those who are not witches are far more limited in power, and even witches who bargain for magic can do far less than a natural witch. Working with nature instead of against it helps.

"Though supernatural beings can be genetic. Werewolves having pups, or turning others through a bite."

For example, and very casually said despite how unpleasant aspects of it were.