Morgase is 6 standard deviations from the mean and Lanfear is 6 SD above the mean. You should use Morgase, Daigian, Moiraine, and Lanfear as markers. You will get better numbers that way.

In other words, if you set Morgase at 1.0 linear strength and her strength is also equal to 6 SD below the mean you will get much better numbers. Work your way up from Morgase and you'll find that Lanfear is far, far above 100 points on a linear scale.

In other words, everyone has been trying to fit the curve onto a 100 point scale. That is a mistake. If you do what I'm suggesting and you stop thinking as 100 as the maximum (e.g. Lanfear might be at 300 or 400 or whatever) then you'll get much better numbers.

Hope this helps