Squabbles about band members not getting paid for their contributions are common. Think about how much of the "Kind of Blue" album has nothing to do with Miles’ original tunes--but that’s the way it is and always has been. Legally the music is the melody and lyric, when there is one. Not the arrangement. I had heard some in the Band were unhappy that Robbie would listen to Levon’s dad’s stories and weave them into songs. Well, that’s what writers do. Robbie sat down and did the work, not the other guys. How much they contributed beyond their parts I do not know. I know that people in the studio sometimes contributed a line or two, uncredited to Beatles tunes. Mal Evans co-wrote some of the McCartney tunes on Sgt. Pepper’s and never received credit or royalties. Anyway, the guy who actually writes the melody and lyric gets the bread. Period.
I wish the Band could have maintained the magic of the first two albums but it was not to be. I was fortunate enough to meet Richard once and Rick twice in later years and even got to play a couple of tunes behind Rick in a club (he sat in with our band). It’s a shame they left us too soon. I did see/hear Levon on his last tour and marveled at how strong a drummer he still was (in his 70’s). What a great voice and spirit he had. Collectively they gave us a lot of great music that still holds up. IMO it doesn’t get any better .