That depends on what controls channeling, doesn't it? if it's genetic, is it completely unlikely that it's controlled by more than one gene, and that having two parents with the right genes could make potentially make you a stronger channeler than having just one parent with those genes? And if channeling is controlled by the soul, who is to say which souls the pattern spins out? If there are ages when channeling is unknown, why not ages when channelers are weaker?

Also, I don't know if anyone has done this before, but I made a plot of the famous bell curve, by using data from the Thirteenth Depository, not including the female Forsaken. Assuming that those data are correct, and that this is a sufficiently large sample, I would say it seems to peak somewhat below the middle. Also, large numbers of novices and accepted are sent away without becoming Aes Sedai. If they are sent away because they are too weak, the peak would be even lower than this chart suggests.

To me, it looks like the average strength today is at something like a third of Lanfear's strength. This in itself doesn't prove anything, and with very little data available from the Age of Legends, I don't see how it's possible to make any solid claims about the distribution being different or not.