EDIT: And a quick check seems to confirm my memory. If you know of a REH story where Conan uses ritualistic magic, I'd be interested to hear it. If not, I am going to call shennanigans on this one.
Closest I can think of is "The Phoenix on the Sword". Assuming that phoenix symbol qualifies as "ritualistic magic" then Conan is using the results of that ritual. He's not preforming the ritual, but in the context of the magic vs. technology thing, a race car driver probably doesn't work on his own car much either at a certain level.
I'd have a hard time accepting someone trying to make the case that Conan is anything but exceptional, across the board. He's certainly a very intelligent person - just not civilized, but he learns to read, and speak languages etc. He wouldn't "have all 18s" because he's not a DnD character, but I think he would have what "has all 18s" would signify when translated out of DnDese.
I think there are matters of degree when it comes to technology vs. magic, and I don't think there is a clear dividing line between the two. On one hand, it seems very easy to see examples of people using magic like technology - throwing salt over their shoulder to ward off evil, for instance. On the other hand, it seems likely that many historical people would have instinctively sensed a difference between issues having to do with gods, ghosts, etc. and those with mundane explanations. I recall reading somewhere that a Sumerian or Babylonian medical text made a distinction between mundane and magical diseases.
Ultimately, I can't imagine that in either a historical or fantastic setting, that the inhabitants wouldn't view magic with a sense of wonder, even if they make use of some small part of it when they need to. That sense of wonder seems to be to almost be required as the definition of magic.