I think Levon had some hard feelings toward Robertson. He did not allow it to consume him. Some believe "Brothers" was Roberstons effort to write the history, because survivors (like the winner) write the history. I am persuaded that Robertson did not act as a fiduciary toward his band mates.
I wonder ....
Jack Bruce/Pete Brown vs Ginger Baker
Sting vs Stewart Copeland
Robbie Robertson vs Levon Helm?
It is a common thing. A good/real drummer is worth his/her weight in gold. While drummers may not generally write extensively they do contribute so much to the arrangement and success of a tune. The Bruce/Brown tune,
White Room, would have been somewhat lame without Clapton's contributions. It would have been very lame without Baker's. Some of the key signature pieces of that tune such as the 5/4 passages are the result of Baker's input. But no writing credits for Ginger. Bitter Ginger. And The Police .... And perhaps ... The John Butler Trio ... And on and on.
I once met a Canadian guitarist who had recorded a number of albums with a group. He also had done a fair amount of session work. He outlined the standard progression of a (as in pretty much any) Canadian group. The group works really hard. They get a recording contract. They make videos. They get air play. They sell records. The song writer comes to rehearsals in his new BMW. The rest of the band come on the bus. Resentment grows like a malignant cancer. The group disintegrates.
Robertson, while not the only songwriter, was the most prolific writer in The Band, I believe. Most of the royalties would come to him.
Yes,
Band of Brothers is a self-serving Robertson narrative. But parts of it are believable. Coke-heads, you can work with. It requires a thick skin, patience, and self-restraint, a lot of self-restraint (the restraint necessary to avoid murder convictions). Junkies are an entirely different and infinitely more difficult thing. And resentful junkies are even more difficult. And it is hard to lose a friend to narcotics - everything you loved about them is gone.