I've stated for years that I believe RJ kept the strength ranking vague so he could do as he pleased with his magic users, but still have a tidy ranking system for them. The way he managed it is actually quite brilliant because there is almost no way he could say something in an interview or add to the text that he couldn't quickly explain via Talent, Affinity or mystery Angreal. Sanderson getting confused is not particularly surprising to me given the number of Channelers in the series and the number of potentially conflicting bits of information the system inherently generates. It's one of the things I find fascinating about RJ's system ... There is nearly always a logical explination for any OP feat that occurs in the series.

I do think he could have flushed out certain things more clearly... Dexterity v. Strength has always seemed too vague to me as well as skill levels. While its clear that some Channelers have great skill and others not as much, it's never been particularly obvious how skill can overcome brute strength ... We have a few examples such as Lanfear handing Rand his ass and late Cyndane escaping Alivia, but the details are insufficient to judge much beyond Lanfear/Cyndane was skilled and her opponents were not. I have always wanted to be inside the head of the skilled Channeler to get a better sense of how the work around things like reversed weaves or fighting someone of the opposite sex ... Lanfear certainly seemed to know what Rand was doing, but HOW she knew was left to our imagination.

The dexterity question is even more frustrating to me as it defies convention in many ways. If you consider boxing as a proxy you could see how a light weight and a heavy weight could actually have a roughly fair fight. One relying on speed and accuracy while the other went for brute force. However, RJ seems to claim that Dexterity was somehow a "normalizing" effect which allowed women to in effect go head to head with the men. In fact we see Lanfear seemingly match Rand force to force rather than truly out maneuver him.

I generally imagine OP to be something of a tennis match pitting a hard hitter against a counter punching player. The contrast in style makes for a legitimate unsurity in outcome, but even in the analogy you would never say these individuals have the same effect to the same degree.