Are good gunsmiths required to manufacture guns? NO!
Look at today's automobile engines. While vastly more complex than those most of us grew up with, they are more efficient, more powerful (per cubic inch), get better mileage, require less maintenance and last much longer. Yet they are not put together by auto mechanics, they are assembled by machines and non-skilled labor. Note that the term non-skilled does not mean the workers lack skills, it instead refers to workers who do not have a trade background, such as Toolmaker, Machine Repair or Auto Mechanic.
So it should be self evident that if a extremely complex engine can be assembled without highly trained skilled labor, guns should be able to as well. What is missing is a proper inspection process. Many manufactures have turned this over to the workers preforming the assembly. Each worker is responsible for inspecting the product for flaws. More importantly is when a flaw is found, it is not only corrected but the source of the flaw sought out and corrected as well. While many manufacturers have embraced this method, many have not, including the firearms industry. As a side note, as bad as S&W seems in this regard, the recreational vehicle industry is far, far worse. I have toured one plant a couple of times. During one such tour, the guild proudly showed off a completed trailer with dozens of pieces of tape stuck to it. He explained this was proof of their commitment to quality, in every one of these items would be fixed before the trailer left the factory. When I asked him why they waited until the unit was finished to inspect it, I got the deer in the headlights look. I then asked why the workers who assembled those parts didn't fix the problems before letting the trailer move to the next stage of assembly, and address what caused the problem in the first place so it didn't happen again? I might as well been talking to a scarecrow.
If an assembler at S&W notices a barrel that isn't clocked to 12, they should not only fix it, but management should get involved and make it so it's not possible to make a firearm with a canted barrel. This is where S&W seems to missing the boat. The most common reason is not having the commitment to stop production to correct a problem.