What I'm really asking is - did they reach some sort of mutual blackmail agreement at some point and agree to go their separate ways?
When you put it that way: I have no idea. Sean or Chick might have been in a position to know if they had been major players then - but they weren't, so they aren't. So no one here knows shit.
But I find this 100% plausible. In real life, confrontations between powerful men don't play out the way it's portrayed in movies. It doesn't sound like a Tarantino, or even a Michael Mann film - it sounds more like two rival mall developers getting the real negotiations done over lunch at the local diner. There's a tacit knowledge of combativeness on both sides, but it's subsumed into a blandly collegial kind of discourse.
So in whatever meeting room (or airport bar) Arnold and Joe Weider sat down opposite each for the financial divorce, I'm sure there was a fascinating mixture of fear, anger, greed, and a narcissistically-shallow kind of familial affection. [Joe was the true father of the man Arnold became; Arnold was Joe's greatest achievement in his self-invented art form of commercial muscle glorification] It would make a great one-act play for David Mamet [though the audience would have to imagine (like they did when staging The Elephant Man) Olympia-sized muscles on the generally unremarkable body of a talented Off-Broadway actor].
