Why Does Luffy's Crew Split Up. He grew up with them and had known them for the majority of his life. The reason behind the crews split was simple.
Ace and then participated in the legendary Summit War between the Marines and Whitebeard. As for the rest they choose to head to Wano Country with Trafalgar D. Luffy heads up the group along with Nami Tony Tony Chopper Brook Pedro and Carrot.
With his goofy personality and brute strength Luffy has endeared himself to many One Piece fans over the years.
With Sanji missing the team wants their chef back and half of them gather to form the Sanji Retrieval Team. The reason behind the crews split was simple. There was no need to bring the entire crew because there was no fighting in Luffys plan. Luffy heads up the group along with Nami Tony Tony Chopper Brook Pedro and Carrot.