A devil fruit user hits the crew and scrambles them all up. It doesnt make them switch bodies. It doesnt make them swap personalities.
It makes them switch vices
So now Luffy is coughing up a lung and making disgusted faces as he chain smokes Sanjis cigarettes.
Chopper giggles as he sways, bottle of rum in his hoof, happily telling Luffy that hes going to scold him for smoking.
Robin well. Robin wants to eat. She wants to eat everything. She wants to eat meat.
Too bad Sanjis busy making all kinds of deserts. Cotton candy, strawberry cake, a variety of chocolates. Not a balanced meal at all, and he is burning through their sugar supply quicker than he would like, but thats not important when theres ice cream sundaes to be had!
Nami is sitting back, watching Sanji work as she tells him all about the time she single handedly saved an entire village from a giant man eating donut. They gave her a medal and put up a statue of her - or so she says
Usopp would probably love to be listening to Namis story. He would enjoy it far more than this book from Robins collection. Hes developing new fears with each page he turns. He lets out a yelp every so often, but he cant seem to put the book down.
Zoro is the only one missing all of the chaos. Hes too busy bellow deck counting all of their money. He would make fun of Nami for this being her main vice - but he finds the act of counting things is actually pretty peaceful. Too bad Nami will later charge him just for touching their gold without her permission.
So, a pretty normal wednesday for the chaotic crew.