A plug for ruling out medical issues that can contribute to poor sleep such as iron deficiency (can cause or contribute to restless legs, can look like a can't quite get comfortable toss/turn thing). Or pinworms, highly prevalent at preschools/daycare, can be carried completely silently or cause minor symptoms of itchy butt at 2 am. Probably others.

With DS we didn't find a medical cause for him needing less sleep than us parents... but we do find he sleeps best with the lights painfully bright.