I see. Can you explain what you were trying to say then with this Place the immovable body in the midst of a crowd of attackers and the result will be an immovable stain on the ground.....
Sure. It was a statement regarding the limitations of power showing that B. in the OP may very well be only part of the story. Equally, the statement that came after the one you reference above was intended to point out the same thing about A. in the OP. Both sides of the coin when taken singly have their limitations but when combined together in synergy become applicable to a wider variety of situations and thus expand the tool set of the Aikido practitioner.