This was proven in "Winter's Heart" and "Knife of Dreams" - despite the fact that the male and female in such a Link don't feel or exhibit a corresponding increase in the amount of Power they can handle, their weaves become more potent.

When saidin and saidar interact, the effect is more powerful even if the effort or Power used is negligible.

EG:
Demandred at the Cleansing: The weave thrown by Flinn's group struck Demandred's protective wards and shielding much harder than it should have, implying that not only was Damer stronger than he appeared, but there was an increase in strength not proportional to the amount of people in the Link. From Demandred's description, this wasn't merely a surprise - the strength of the attack was sufficient to put him immediately on the defensive, and he is not far behind Rand/Lews Therin in strength.

The Aes Sedai and Ashaman at the manor in KoD: Though both channelers were using small amounts of the Power to incinerate the Trolloc corpses, Cadsuane remarks that the flames were more intense than they should be considering how little of the Power the Aes Sedai were channeling - the inference is that the Aes Sedai had Linked with their Ashaman Warders, and both were just channeling a trickle of the Power.

The Cleansing: Rand's plan required using saidar to push the taint off saidin - his plan worked because saidar behaves in a very powerful way when exposed to saidin; it gains extra "force"/"polarity"/"dynamic energy", and this force is what enabled the taint to be pushed off. It wasn't what Rand and Nynaeve did - it was the basic behavior of the two sides of the Power when brought together that enabled the taint to be Cleansed.