What you have are large suburban/urban (high income areas) with a concentration of the best education and prep work. National Merit scores are a reflection of concentration at the top. Another factor is the number of mediocre students you can get to take the test. The more mediocre students - the lower the cut score for 99 percentile is.
I wonder if it makes sense to relocate to Arkansas your Junior year?
Think I would prefer Wyoming. {:-)
No, most of the scholarships wouldn't pay your moving expenses.