J-Bar brings up a good point. Joe Hobby and his clan used to butcher S&W or Colt revolvers by bobbing them. Some went so far as to drill them out so as to lighten them further. Of course, ignition suffered.
The solution is to test the firearm with the type of ammunition intended to be used with it. If it doesn't go bang, then fit a new hammer or switch to ammunition that will fire reliably in it. It costs money but that's the trade-off for a lighter hammer.
Personally, I hate bobbed hammers. My first Python had one and I immediately bought a replacement hammer which I fittted. The Python was $300 plus tax and the hammer was another $50.
Finally, there is a business perspective to gunsmithing. A gunsmith may accept the job in the pursuit of generating revenue. Thus (s)he will take the job whether it is in the interest of the client or not. Other gunsmiths will reject the job and explain why. I recently declined working on a gun because what the customer wanted was not worth the work/costs involved. If a gun is worth only $150, why put $600 of work into it when its completed value will not return a yield on investment? That is, the customer is throwing good money after bad. There was no sentimental value attached to the firearm (grand dad's gun type stuff) so why bother?