We've seen them get super aggressive when presented with exceptionally strong women certainly, but the system also lends itself to recruitment of women weaker than themselves. Think about the politics of the Tower and then imagine an Aes Sedai actively recruiting a woman who will one day be considered superior to her in the hierarchy. It's probably one of the major reasons the majority of Aes Sedai show no interest in active recruitment. Why go find a bunch of significantly stronger women if it's only going to displace your potential to achieve within the system. The system is far more aligned with bringing in"middling" channelers than channelers at either extreme.

Up until Egwene opened the Novice book to any woman and they started seeing floods of women at a variety of strength levels most Aes Sedai wouldn't see an advantage to recruiting a strong women unless it came with a political agenda such as Elayne. Post Egwene's decree though most Sisters realized that there are as many women weaker than them as stronger than them so their relative place in the hierarchy would remain in tact.