Don Firth, you have expanded the traditional ratio of communication between picture and words to infinite, since division by zero is axiomatically forbidden. :) Fine picture!
I am surprised by the absence of reference to a part of the second sentence in this thread way back in 2001: "I now prefer to play the bouzouki, which although it has eight stings, they are set in four courses, so in reality there are only four differntly tuned strings." This would be on a good day, and that would apply to all the double strung instruments- poor tuning is common, and perfect tuning so that all the A notes are perfect multiples of 440 Hz or perfect unison, for instance, is rare, especially at the end of a tune. The slight beat from having 440 adjacent to 439.95 imay even be a part of the ring on mando family instruments. Certainly the sympatetic reinforcement of harmonically related noted is greater with more strings. The fallacy in all of the back and forth is that, technique being equal, the body of the instrument will trump everything else - one note by Pablo Casals or Yo Yo Ma is equal in presence to anything Andres Segovia OR Leo Kottke could do. Greater or lesser is in the ear of the listener.
Carter B