It's worth remembering that identical speed, treadwear, and traction ratings by no means indicate the performance of a tire.
For one, these ratings (aside from speed) are set by the manufacturer, and don't actually correspond to any real formulas or statistics, nor are they held to any standards by any outside agency. The company can basically put whatever they want on a tire, and even in the best scenarios, the numbers only have any real meaning in relation to other tires made by the same company.
Secondly, the majority of tires on the market are designed for economy, and they get the majority of the ratings. Performance tires are a niche product, and, basically, all of them end up falling into the ZR and AA ratings. It's completely plausible that two tires from different companies, but with the same ratings, could have such a difference in actual performance.
For example, the Dunlop Direzza DZ101, the Hankook Ventus RS-3, and the Falken Azenis RT-615K share a W speed rating and a AA traction rating. However, the performance is vastly separated between these tires, with the Direzzas performing quite disappointingly, and fitting into a "sport compact" type of tire, the Hankooks being a very high-performance street tire, similar to what's equipped on exotic cars from the factory, and the Azenis are barely separated from a real race tire, not much more than a slick with some grooves cut into it.
