Energy transfer is dependant on the volume of the wound channel that the bullet makes.The largest wound chanels that I have seen were made with fast expanding bullets at high velocity.A large slow moving bullet that does not expand much actually makes a smaller wound channel than a faster moving but smaller diameter bullet that expands to a much greater diameter.As for the silly analogy about the brick and marble let us compare their weights.The brick would probably weigh a couple of pounds compared to an ounce for the marble.So in other words the brick probably weighs 30 times that of the marble.For this analogy to be accurate the heavier bullet would therefore have to weigh 30 times that of the lighter bullet.If the lighter bullet was 150gr which is a common weight the larger bullet would weigh 4500gr. How many people use a 4500gr bullet?The analogy doesn' t really make much sense does it?Giving a person the choice of being hit in the chest with a 150gr bullet fired by a 30-06 or a baseball thrown by hand would be just as accurate.