I disagree about the new sherif being an unnecessary complication. The characters have been getting away with doing what ever they want. That wouldn't happen in real life. She adds normalcy back to the show. She's a hard-ass by the book sheriff and to me refreshing. Most fantasy shows like this, when all
the characters buy into what ever the premis is, removes it even further from being somewhat grounded. You need her to reinforce that this wackiness is happening in a fairly normal situation.
It's Sleepy Hollow. "Normal" and "grounded" are the last things we want in this show. The crazier it gets, the more we love it.