If you're getting FBA, it's just an optimization of throughput. If there's enough folks in your area with Prime, trucks are going around your neighborhood daily anyway, so it's better to send a full truck, even if it means things get there early, then to send a partially empty truck twice.

Amazon likely does not have separate Prime and Non-Prime lanes in their warehouses. It would be a redundancy and add additional complexity that would increase costs/reduce profits. Since customers never see the warehouse there really wouldn't be any benefit to doing this.

Are we in the game where an event happens randomly, and we’re trying to guess whether any of our actions, if not worshipping Bezos directly, might have an effect on delivery times?