FWIW: the reference to "small C conservatism" was specifically to make clear that I was using the word in its traditional sense ("change is presumed bad absent evidence") and NOT referring to modern political divisions.

In fact what you're describing is exactly the disconnect: libertarianism is very much not "conservative" by traditional standards. The fact that they live in the same party in the modern US is an accident; it doesn't follow from their philosophies at all.