Hey Slicepong, yeah we are both well thanks hope you are doing good too! Your absolutely right, the legs and body come first and are where the main energy in the shots come from rather than generated too much through the arm alone. The arm is really used as almost the final part and the area which should be relaxed and whipping through the ball with acceleration, if you try to create all the energy with the arm it will be too much effort and technique will be lost.
The powerful and bigger muscles in the legs and core need to be maximised to get quality into your shots, look at players like Fan Zhendong and Timo Boll, they are so low and use amazing amounts of legs and body rotation to allow the arm to then be relaxed and play their strokes. Your also right, many players don’t do this that well and it can hold them back. So definitely keep working on that mindset and using the legs to explode! 🙂