using the Carpenter you choose 1 deck (for example ships cost 30) and you take the three cards from the top of the deck. You choose 1 of these cards and put the other two cards at the bottom of the choosen deck.
While you choosing the cards the other player may do there turns. They don't have to wait.
You can do this for 1 wagon and/or 1 chip. You buy the transport vehicles at half price.
That would play a bit quicker than being able to look at all the decks