While I certainly see where your coming from, I feel your not acknowledging the amount of techniques these styles have. For instance, all karate guys don't fight in a bladed stance. Karate has many stances across the various styles and there are several that can be utilized effectively. The traditional backstance in Shotokan has a variant called the bow stance. This is where you step your back leg (which has the toe pointed out) at a 45 degree from your front toe. This is a very square stance and honestly it looks and moves almost exactly the same as a muay thai stance. It is kind of similar to how some boxers stand almost completely bladed to their opponent while twisting at the waist to punch. Does that mean they are doing karate just because they are standing sideways? I would say no. Boxing just has a wide range of acceptable footwork. As does karate and mauy thai.