Legally, the issue isn’t what they were thinking when they hired the actor, it’s what the intent and effect was when they went to market. (Even if there was documentary evidence that they actively sought out an actor for resemblance to SJ’s voice from day one, the
only reason that would be relevant is because it would also support that that was there intent with the product when it was actually released, not because it is independently relevant on its own.)
Whether or not they had any interest in SJ’s voice when they hired the other actor, they clearly developed such an interest before they went to market, and there is at least an evidence-based argument that could be made in court that they did, in fact, commercially leverage similarity.