The moment of body rotation in Shinji swim

[swimust]

Hello CoachDavidShen and Ladyfish,
You may have missed my question on the other thread with all my mumbling which maybe meaningless sometimes.
CoachDavidShen said that I make some ineteresting and valid points so here is my question:

2 days ago I found that the best moment to switch from hip roll to body rotation (shoulder twist) is the moment the deltoid of the spearing hand is submerged under water. This made a big difference and I believe that now I found my body rotation and I do it on time and in the correct way.
Do I have confirmation from you about this or not? I will not be disappointed if thats not the case. Its just a part of the learning process and you seem to be willing to help (a lot).
Thanks for any tip.