403.5. If 2 or more cards are Recycled to the Main Deck simultaneously, they are placed on the bottom of that deck in a random order. Example: Garbage Grabber has the ability "Recycle 3 from your trash, [1], [E]: Draw " To pay the cost of activating this ability, its controller chooses 3 cards from their trash and places them on the bottom of their Main Deck in a random order.
403.5.a. If 2 or more cards are Recycled to the Rune Deck simultaneously, they are placed on the bottom of that deck in the order of their owner's choosing.