Yea to create Power Value to be good indicator you would have to take a lot of data to have a more accurate power value. gameshape for example you would have to look alot on how it impacts how the player perform in a game on average to know how it would adjust the power value, and adjustments also be made given that centers are much higher in salary. Like you said it will always have flaw, the current ranking themselves also have flaws. Anything that is based on algorithm is made to be as best predictor.
Could you send me the main suggestion forums please? I like to just send the link for this on the suggestion forum and brief explanation