Procedure of exclusion.
Arthur is indicated to be rich in ORS and in GGGB he could only become so if Ashley was his partner (since he would pick her birthdate for the winning lottery ticket).
Also, Arthur only appears on a path in which Lena agreed to work with Seymour. And incidentically, this choice impacts Jess partner (Dave if Lena works with Seymour, Ashley if Lena refuses Seymour).
Never played his path to the end. But he potentially could become rich some other way, like pimping out his daughter or other vulnerable women. Or some contrived series of events at his workplace.
But that's solid evidence for your theory, the one path lottery ticket.
Your theory implies that the canon ending for Ash is with Arthur every time but if she lands with a Good Jess AND Lena doesn't work with Seymour (slight tangent, when does that lock in? Can Lena do one or two shoots with Seymour, but not sign the contract?).
Jack never seems to be committed to Ash, so ORS at best exists in a small slice of the multiverse after GGGB. Which is honestly kind of lame, and makes me side with the folks that believe there's too much crossover between the two games.
Ash never reunites with the BF? She never becomes a pornstar? It's only Arthur or Good Jess?