To reply your question,
Closer to Robert’s, but I dont use hip the same way with Andreas.
That is because we all have different style and different style has different core philosophy.
Also, in my lineage, and I can speak for my lineage only, as Robert has mention, hip movement is less pronounce as time goes by because hip is a part of the body and snake movement must not emphasis on any part to get a smooth operation, due to as you know, “snake” engine is the emphasis of my lineage.
Ultimately, it got to get to the point of — as the Intention makes the power is there. emphasis hip movement can become an issue or “break point of the chain” if not handle properly.
As for how to handle the hip and knees and every joint of spine…etc, that is where the Six dimensional force vectors balancing comes in to play. anything excessive create problem.
Thus, in the above one needs not to align the body similar to the traditional generalization way or require how each joint suppose to be alignt…etc. because the technology is suppose to be so simple and use both at static and dynamic state.
It is a different paradigm compare with the general – sinking, rooting, standing post,
power generation.
further more, in my lineage, we dont generate power from hip or spine. also, the power generation has a few components for acceleration and propel outward, it is different then the usual thinking of using muscle or ground power. It is much complicated then that to analyze.
And ofcouse you always need to take in the consideration that every different style as a different way. and the above is just a way.
Hope this help.
A side topic:
This also open up a topic called Kuen Choong or Seed of the martial art. Since as most know Cho gar has lots collection sets of different style, thus, my late sifu Cho Hong-Choy was very particular to how the set done according to the Kuen Choong.
In an occation, I was doing my SLT with CLF they of hip move and step size, I got scold big time on this. He told me, " dont be Paan Chat (stupid) how the heck is that way of practice produce the short jin and gentle type appearence? you waste your practice making this type of mistake. now your practice not benifit you as CLF also not benifit you as WCK. be careful on the Kuen Choong. Know that before you do your set. cant be fuzzy."
So, one cant use cookie cutter one size fit all for everything, especially when it comes to power generation because every style or lineage is a custom made.
These days the term Kuen Choong seems like a vanished word. Cho family has lots of details description because Cho family is a Martial family for generations. As I was told ,for generation Cho family ancestors also earn and hold title in Qing Government martial school examination. So, Cho is very particular and precise in the ancient time because these people are real pro. After my sifu Cho Hong-Choy passed away, I have not yet met a person in Cho family go that deep in analized art, hope I could met some one someday who has the same level of understanding as my late sifu.
according to my sifu there is a reason for why thing was done the way it is . and also it often is not a single event but related to the whole system, and also knowing the Kuen Choong is knowing the strength and weakness of the art.