Take a body builder, and a 5 year old kid. They have to push a car for one mile.
Who's going to do the lions share of the work?
For the 15 minutes it takes to lighten a set of heavy rollers with a dremel... I don't understand why or how anyone would even try mixing weights or types for that matter.
There is nothing mystical in finding the correct balance for your engine but some people insist on doing things with a mystical approach. God bless their little hearts.