I'm not sure so much about colloquial vs sophisticated, but "wheelhouse" feels more sensible than "big-wheel" as a source. That doesn't seem to be the received

I'm not sure so much about colloquial vs sophisticated, but "wheelhouse" feels more sensible than "big-wheel" as a source. That doesn't seem to be the received wisdom at this point though. One 'non-etymology' I regret is that Linux _isn't_ a recursive acronym for "Linux Is Not UniX".