Fascism isn't really "far right" in the same way socialism and communism are "far left". Fascists believe in a mix of typically far-right and typically far-left ideas. You need more than one dimension (probably at least three or four) to fit fascism into the political spectrum.

So if one of your axes is "economic protectionism", another is "level of state intervention in the economy" and a third is "nationalism", and fascism is pegged to the max on all of those, it's not too unreasonable to call it "national" (because of the first and third axes) and "socialist" (because of the second).

It is almost as if all combinations of political and economic systems can't be mapped to a one dimensional spectrum...

Yeah but maintaining America's rigid dichotomy ensures we never progress outside entrenched corporate interests.