Regarding the order for learning, I suggest that since we ski from the ground/snow up, we should also learn the proper movements in that order. Thus, tipping comes first (with the required flexion to support the tipping). Upper body separation (counteracting and counterbalancing) are in support of the tipping, so you really need to understand the movements required to tip well, before worrying about what your upper body is doing. The CA/CB work comes into play more naturally when the "light bulb" turns on for the skier as they begin to understand that to tip well there are things that their upper body will need to do in support of the tipping.