Wayne WernerOf course, I could just use this, but I don't like going in order so let's `comm ... | shuf -n1` to give me a random, single, missing element.
Now if we just call this all SHELL and handwave it away and just look at our vim macro, things get way less complicated!
:4^M:r!SHELL^MI- ^[w*Nvip:sort^Mnyy+w*P2xyypVr=
Assuming you don't know anything about vim, these are just keystrokes. Except ^[ & friends are achieved with the aforementioned ctrl+v, ctrl+[.