Sometimes, my cartomancy teachers used two tarots decks to answer a client’s question.
Especially in delicate matters of personal choices regarding career, investments, long term choices.
The reason of using two decks is based upon the natural laws of attraction of similaries, repulsion of opposities and also environment mirroring and checking life expectations.
In easier words, one deck speaks for the person and the other for the environment or the choice. Some special occasions need special methods for special people. A special post needed by someone special indeed.
Cheers from the Sphynx’s Sons