"The Night They Drove Old Dixie Down".

Let's do a thought experiment -- who from Led Zeppelin could play in The Band?  Bonham, no way.  Plant, it's a few decades early in his development.  Page, as an acoustic player he could bring a little English folkie sound to the group.  Although I'm not sure they need that.  Finally, JPJ would slot right in with Danko moving to vocals.

Who from The Band could play in LZ?  Robbie R. could and so could Garth.  I think that would be the most interesting 2 lead guitar group going.

I do somewhat similar thought experiments all the time, including with members of The Beatles. In the documentary on The Band, George Harrison states he instantly felt a kinship with Robertson, hearing in Robbie’s guitar playing an emphasis and focus on contributing to the song itself, to the entire production, rather than playing as a single instrument---the way many guitarists do.

It’s the ol’ "ensemble"-style playing I am so attracted to. That’s why many of my favorite players are studio musicians. Emitt Rhodes told me the best musician he ever worked with was Jim Gordon, a very favorite of mine as well. Another is Roger Hawkins, the drummer in The Swampers, the studio band heard on all the great recordings that came out of Muscle Shoals in the 60’s and 70’s. In an interview in Modern Drummer, Jim Keltner stated he wished he played more like Hawkins.

If you watch and listen to the finale of The Last Waltz, you see and hear poor ol’ Ringo Starr, trying to remain relevant by playing along with Levon Helm. It’s sad: his playing is SO tired, SO sluggish. There is no way he could have been the drummer in The Band.

There are two English bands whose records allow a direct comparison between the playing of three of that country’s most well known guitarists in the same "setting": The Yardbirds, and John Mayall’s Blues Breakers. Eric Clapton is heard on only some of the songs on The Yardbirds’ For Your Love album, the rest and the next two albums it was Jeff Beck. Jimmy Page is heard only on their last---and drastically weakest---album, Little Games.

John Mayall’s first three albums feature the playing of first Clapton, then Peter Green, and lastly Mick Taylor. Dave Edmunds---one of my favorite UK guitarists---was considered when The Stones were looking for a replacement for Brian Jones. I’m glad they chose instead Mick Taylor, allowing Dave to embark on his fantastic solo career. When Dave wanted a guest guitarist on one of his albums, he gave Albert Lee a call. Albert played in the bands of Emmylou Harris and The Everly Brothers for many years. He also has a number of excellent solo albums.

I better stop now: this could go on for quite some time 😉 .

@onhwy61 

Who from The Band could play in LZ?  Robbie R. could and so could Garth.

Garth -- OK -- he can play just about anything. I love The Band and I'm not a Zep fanatic by any means but RR?  Maybe you're joking? 

No joke at all.  Garth would provide instrumental texture and density to the LZ palette.  It's a role that JPJ did for them in the studio.  The original Jimmy Page concept for LZ was as a twin guitar band with Terry Reid as the vocalist, co-lead guitarist.  RR can't sing, but he rock a Strat or Les Paul with the best of them.  As an added bonus, LZ's lyrics would have been upgraded.

@onhwy61 ”John Bonham couldn’t play in The Band. No way.”  
“No way”??? How is this statement logical?  
Levon could be his typically great self, singing wonderful lead vocals, singing great backup harmony vocals, and playing a multitude of instruments.
The musical difference in the songs of The Band and songs like “Tangerine,” “Hey, Hey, What Can I Do,” “Boogie With Stu,” “Bron-Y-Aur Stomp,” “Your Time is Gonna Come,” “Black Country Woman,” “That’s the Way,” “Gallows Pole,” and “Down By the Seaside,” is minimal.  
Furthermore, each of those songs feature extremely sensitive, tasteful percussion that serves only to improve the song.  
John was an extremely sensitive and intuitive artist who simply loved music; simply loved good songs. Bludgeoning the skins was not imperative to him. It was just another thing he did. In the case of Led Zeppelin, it came in handy.  
Again, this was not imperative to John’s artistic expression, just another component that may or may not be useful depending on the song.

“Plant, it’s a few decades early in his development.”  
Come again?  
Plant is a perfect contemporary of The Band (‘68-‘76). If that is true, and his vocals were, at best, equally good (at worst, demonstrably worse) in advanced age, how can your statement on Plant’s “development” make any sense?