Hi Rachel
I think you may be getting ESA confused with IB.
ESA (WCA) requires a total 15 points regardless of mental or physical health.
IB (PCA) requires 10 points for mental health, or 15 points for physical health.
If you fail to score either of these, 15 points are required when you add the two together. However in this instance, less than 3 points for mental health will be disregarded and 6 or more points for mental health will count as 9 points when added to your physical health points.
Derek