I think it's an idea that would be a lot of fun John. And they might add those notes he can't hit anymore. I've been close enough to hear Rick on Sundown and while I love his bass playing I think there's a reason Mr. Lightfoot does not provide him with a live mic. His band has certainly changed over his career and the addition of some harmony might be cool.
It might make an interesting poll question. I know there's more than one member here that would prefer he leave the band at home and just play the whole set solo and acoustic, LOL.
Bill