You do realize that this was already sucessfully implemented in New Vegas? Parting Big Guns, Small Guns etc in seperate Skills was never that much of a brilliant idea.
Skill Mechanics aren't carved in stone. Fallout was never a perfect game, even if we all love it.
Never tried to convince you, as I can see where you're coming from.
But then you should change BG and EW to have same base value as SG, otherwise you're going to start with 30 EW and "Laser Mauser" will not help you at all.