The further up the specialization ladder you travel, the more scientist-like the doctors become until you reach the pinnacle where doctors at research hospitals are doing ground-breaking treatments and publishing the results.
The gulf between the average MD doing GP and this pinnacle is huge. Much larger than most people suspect.
I don't understand what you're trying to say. First, the average MD isn't a PCP with generalist training. In fact, a lot of PCPs now are IM specialists. In fact, when talking about PCPs, there are many cases when no generalists come into the equation at all -- kids should see pediatricians as their PCP.
The gulf between the average MD doing GP and this pinnacle is huge. Much larger than most people suspect.