John, that is certainly one way to look at it, but I try to relate to a live situation that I'm familiar with - like when I was in 4-5+ pc bands. The same band had to play both Misty, and Rock around the Clock, and our playing style was mostly all that changed - we used the same drum kit, same bass player etc. I like the consistency of hearing a tight core ensemble, backing up a strong vocal(s), and playing the songs with a little bit of the "flavor" of the performer ... to add a personal touch.
My go to ensemble is: Piano/Rhodes/Organ-bass-guitar-drums-and either a sax (solo, or section) sound, and a brass sound. These were all the staples I had when we were in bands years ago, and had basic synths to add some color to the sound. Of course, I'll add a few other sounds because they're available, but my basic (band) unit travels with me from genre to genre.
I'm not trying to start trouble, but it's not likely that you saw Johnny Mathis and The Comets, on stage together, playing those two selections you mentioned, is it?

You made all good points, but I wanted to add a different perspective ... just for fun. Happy New Year!