It's cute, and gets at something real, but it's overstated. The first question is "are these things mutually intelligible", with an answer on a spectrum between "yes, perfectly, obviously" and "no, not at all, obviously". There is a huge gray area that stretches pretty far from the middle in which contingency, identity, community, and nation building projects (both military and literary) move the lines around quite a bit... but as we near either pole that factual question dominates. I think. I'd be interested to learn of counterexamples.