"Most made their money from albums they did no drum on"
Really ? Which ones ? Be specific.
"Mullen has been a drummer all of his career. He is a pure, active drummer. I doubt Watts is active in the recording scene."
You DOUBT or you KNOW ? Watts is a founding member of th eStones, one of the most successful bands of all time.
"Ulrich gets a bigger cut of the Metallica share so his success is a product of his shrewd negotiation. "
No, he FORMED the band. just as Larry formed U2.
What you don't know is quite a lot.
"Mullen is a selfless band leader, never demanding more than his 1/5th share even though he is the band founder."
And Lars is a band founder. As is Watts. As is Grohl. etc.
"Henley and Starr also mix their profits with music they don't drum, but play other instruments on."
Being multi-talented is a good thing. They SHOULD get more money.
"If that is the case, maybe we should add up Mullen's investment in Elevation Partners in Facebook and he will zoom past all of them for the top spot."
The article states "Net Worth". Maybe it's already included. Of course then you'd have to add everyone else's investments in there too. Ask the author if you care.