Exactly hat proof exists that Nynaeve is weaker than Rand at this point? There's absolutely nothing to say who is stronger. We know Rand has been using LTT's memories, but that's it. If they struck out at each other, he wins by virtue of that fact alone.

We have no clue if Nynaeve, who had been channeling far longer but was blocked, was weaker or stronger than Rand, who as a man would have greater jumps in strengths. But we also know Nynaeve was forced, and we also know Rand started out much stronger than other men seem to.

To take Egwene's hopelessly naive assessment as proof of anything is absurd.