Here's what we know:

We know with reasonable certainty that the spread of channeling strength from Daigian to Moiraine is about 3 fold. Meaning that Moiraine is about 3 times as strong as Daigian.

We also know that Daigian is so weak that she is barely above Accepted level (making her the absolute bottom of the Aes Sedai strength range).

So we know that the spread of channeling strength from the weakest modern day sister to the strongest category (which included Moiraine, Romanda, Lelaine, Siuan and Elaida) is 3 fold.

We also know from Siuan, that if she was at two thirds of her old strength, she would be as strong as most sisters.

This gives us the strength level of the average sister, which is two thirds of the Moiraine/Siuan level. Meaning that Moiraine was 50% stronger than the average sister.

We further know that according to Aviendha, Egwene can match or exceed the strength level of Amys plus Melaine combined. Amys is just short of Moiraine's strength, while Melaine is stronger than an average sister. Meaning that at the very least, the two of them combined are about two thirds stronger than Moiraine.

E.G.

If Dagian is a 10

It puts the average sister at 20

Moiraine at 30

Amys plus Melaine at about 50 (which then is roughly Egwene's strength level)

We further learn that Moiraine believes that Egwene plus Aviendha could approach Lanfear in strength.

What do you know. Egwene at 50, plus Aviendha at maybe 40 (she's not at her full potential yet), gives you around 90. Not quite Lanfear's strength, but very close to it.


We also know that Egwene believes that she, Romanda and Lelaine together could possibly match a male Forsaken.

Egwene at 50, plus Romanda and Lelaine each at 30, gives you 110.

What do you know, just enough to match a male Forsaken of Rand's strength level.

We see Flinn - the strongest Ashaman, plus two average sisters, match Demandred very closely. Again, what do you know, 2 average sisters at 20 strength each, plus Flinn at around 55 gives you Demandred level of around 95.

We see 5 sisters barely able to hold Logain, who is presumably around a 90 level channeler.

Even if they are all 5 weaker than average (put them at 15 strength), their shield should still be at around 75 strength. And we know that you can be weaker than someone and still hold them shielded if they aren't embracing the source. So a strength of 75 is pretty much spot on to be borderline between what Logain could break free from.

The examples go on and on.

Together it makes a pretty much irrefutable case that the Bell Curve can only fit if the average strength female is around Egwene's level and all modern Aes Sedai fall well below average.

The conclusion is that the Bell Curve applies to the channeling population of the Age of Legends, at which time Egwene would have been an average strength channeler at exactly half the strength of the strongest possible woman.

And all modern Aes Sedai would have been considered below average by some margin. In fact, most of them would have fallen in the lowest 20% of Age of Legends channelers.

This is the only way that all the evidence fits a Bell Curve scenario.