So, there is no such thing as a division between unequal outcomes of “morally arbitrary factors” and unequal outcomes of acts based on personal choice, in a free society. Free will always occurs within a certain deterministic frame; both elements are profoundly embedded in one another. Rawls probably understood this reality when it comes to wealth, which is why he wanted continuous redistribution, yet he still uses the distinction as a way to constrain the scope of his Original Position. More importantly, a deterministic frame doesn’t negate freedom of choice and rightful ownership of—or responsability for—its consequences. It would simply be absurd to contest the legitimacy of personal agency and its outcomes because they occur within a deterministic frame; that's a characteristic of all human action.