Often there's no meaning to songs, and this may be the case here. I always loved Band on the Run album and will ldig it out again, but having looked at the lyrics I think he may have made them up as he went along
If you kisten to McCartney's exsceelent 'Ram' album you will hear that he just adores word-play and uses phrases simply for the sound rather than the meaning.
I think he was still enjoying doing exactly as he pleased as a solo musician after all those years in a band with a concensus to deal with.