You write, '[Divergent] pieces are stronger than either non-divergent piece, but weaker than the unrestricted compound piece.'
This seems exceedingly unlikely. You seem to be claiming that a piece that moves as a Queen but captures as a Knight is stronger than either; in fact, read strictly, I believe you are claiming that a piece that moves as a Queen but captures as a Bishop is stronger than a Queen, even though it has strictly fewer moves.
I believe conventional wisdom is that such pieces (which George Jeliss calls 'snipers') usually have a value that is somewhere between the strengths of the non-divergent pieces, closer to the capturing component than the non-capturing one. (Though I'm certain it is possible to craft examples that violate this rule.)