Moghedien's shield never landed on Nynaeve so all we ever saw was that she had an extremely sharp edge to it, as did Nynaeve, but her weaving is a total mystery. Her shield on Liandrin is rather a moot point given the strength difference here, but again, we never saw more than the extremely complex knot she incorporated which speaks more toward skill than anything else. Liandrin's only chance of breaking a shield put in place by someone that much stronger was to pick away the knot. You are assuming that the weave itself was the exact same as the few shields we've seen when it could very well have been of totally different complexity. We have yet another clue from Moghedien herself ... she looks it over and notes that only one of the Forsaken could have escaped her shield, which could imply that the weave itself is of a better quality than the "half trained children" could have managed.

Lanfear's shielding of Asmodean is another hint that shielding was more complex in the AoL ... she managed a partial shield on a man of superior raw strength that held him for months. That goes well beyond an assumption that she used the same weaves as the Aes Sedai to block him from the Source. She also states that his unwillingness to accept pain is why he could not escape, implying there was more to her shield than what we've seen from others. Moghedien escaped Nynaeve's shield in seconds and we all know she doesn't like pain either.

What evidence do you have that shielding was not a result of Aes Sedai searching for effective ways to stop males from destroying the world? We know Aes Sedai did a lot of research around how linking worked as part of stopping mad males, or at least controlling them. Given that Tower law requires a male to be brought to Tar Valon and put on trial, shielding would have been a massively important skill for early Reds to have mastered.

The fact that it also worked on women would have been incidental and what would prompt Aes Sedai to find more effective weaves to block other women. Aside from knowing that there was a lot of politicking in the early days of the Tower and probably more than a few conflicts ending in dead pre-Tower Aes Sedai, there is nothing to suggest Aes Sedai hunted down, shielded and brought to trial women who falsely claimed the Aes Sedai title and even if they did this happened within a very short timeframe so it seems far less likely that women would have spent a lot of time figuring out more effective ways to shield other women. Especially since they were already in large groups and linking was an option.