Keep this statement of your in mind, as I'm now going to disprove it...


Talking quietly among themselves, the four Kinswomen took their places where they had opened their gateway some hours earlier.
They eyed the corpses in the street and shook their heads, but these were not the first dead men they had seen. Not one would have been allowed to test for Accepted, yet they were calm, sure of themselves...

...The familiar vertical slash appeared and seemed to rotate into a view of the main stableyard in the palace, a hole in the air nearly four paces by four, but the view through the opening, of the tall arched doors of one of the white marble stables, was a little off-center from what she expected.
KoD, Siege.

Now, you said two weak sisters cannot match a strong sister. That might seem fair till you realize the implications of what we're seeing here.

Four women too weak to even be Aes Sedai (less than strength 10, according to you) are linked in this situation. Let us put their average strength at 8. Considering the linking loss, they're approximately of strength 30, by your estimates.

Now, by this calculation, the linking advantage gives a circle of strength 30 the precision to nearly match a channeler of strength 100 (Rand)! How is that possible?

If they were, say, strength 25, linked they would be 90, and given the linking advantage, they'd nearly match the strongest possible channelers.