Springs are of a certain power to perform a certain job; resetting the trigger or accelerating the hammer and giving it enough force to set of the primer.
However, that force is lessened by friction and a good action job will include polishing the parts that bind. A good gunsmith will not work on a revolver unless it has been shot around 500 times or more to see where that friction occurs.
If the friction is properly reduced, a lighter set of springs can perform the intended purpose very well while giving greatly improved trigger characteristics.
I guess I was lucky to find a very competent S&W certified gunsmith who also was an avid shooter and kind enough to share a lot of his kowledge with me.