From what I'm getting here. In your theory of "IP" you use the dantien in addition to localized muscle groups to create power. Kind of like the transmission in a car, you use weaker but centralized muscle of the core area of the body, specifically the iliopsoas, and the tensor fasciae latae (dantien) to help recruit more power and stability for localized muscle groups.
If I'm reading this right, there is also the theory that high level dantien guys can move their appendages with only the muscular contractions of the dantien. However, again if I'm reading this right, it's still most beneficial/powerful to recruit local muscular groups (muscles of the legs, arms etc) when attempting to do things as powerfully as possible. This would be kind of like chain linking the muscular groups together from the dantien out.
Is this correct, or am I missing something?
It's interesting to note that Sagawa Sensei in his later years was so feeble that he could not open a jar of food. But when he got out on the tatami, he would throw you around like a ragdoll. Did he need to recruit his local muscle groups to be powerful? If you believe the stories...then no. So there has to be a better way. Maybe to be truely powerful, you have to give up being powerful(not sure if i'm ready yet).
I'm going back to the tatami...training, training, training.