Aloha all
Interesting reading this thread. I have a slightly different view to offer up to the group.
To me this question is like that of the conumdrum of the meaning of life the universe and everything in a way (okay, okay I know the answer is 42). It is a subject you can consider for as long as you like and yet never reach a group agreement on. Everyone will have their view and who can really stop someone having a differing view in the light of no right or wrong answer.
So I would humbly suggest that power share is whatever you wish it to be. What you wish it to be abd what it is are possibly two different things anyway. In fact my view would be it is an ever shifting sea and so hard to define at most times except at either ends of the spectrum. This makes it a fantastic topic of discussion for finding others thoughts but something, perhaps not to loose sleep over, as you will never find the definitive answer.
Just a thought or two. (Ducks while rest of thread throw stuff at old Dragon.)
Mahalo - Dragon (Hope some of this made sense)