My expectation is that the outcomes would be similar for the common issues, and would start to deviate as you got into more uncommon problems. A doctor will have a lot more "background knowledge" to be able to consider things that are outside the every day. At least in my mind, it's not unlike someone in software development with a degree in it vs not. For most things, the person without a degree will do a fine job; but for some things, they won't be able to consider many of the possible options/tools, because they just haven't been exposed to them.
correct. except the person doesn't even know when they don't know. and that's the most dangerous part. If you at least know what you don't know, you can re-direct to the right resources.