It could be a coincidence but looking back at pre timeskip sabaody I noticed something interesting. When the strawhats initially planned on splitting up and running they split into 3 groups
Those 3 groups being
- Luffy, chopper, and robin
- Zoro, brook, and usopp
- Sanji, franky, and nami
Off the bat it nothing seems to significant in how they’re grouped up. That’s until you look at the monster trio power ups during the wano arc
First off there’s luffy and chopper
We found out during wano that like chopper luffy also has a human human fruit just a different type. They also both have specialized forms that most normal zoans don’t along with old men forms when exhausted
Then we have zoro and brook
During wano zoro got his hands on enma. A blade named after the king of hell that is said to be able to cut through it. Brook is obviously another character with connections to themes of hell, death, and soul themed powers
Finally there’s sanji and franky
In wano sanji had a lot of ties to the power of science. Starting off with the raid suit but ending the arc with an exoskeleton. Sanji lowkey kinda being a cyborg because of it. Coincidentally franky is also a cyborg that uses the power of science to enhance his body
As for robin, usopp, and nami idk lol
Maybe they will get power ups in a similar way. Like robin having a zoan, usopp getting hell/soul related powers, and nami getting a modified body
That or the opposite where the monster trio next power ups mirror their abilities next in some way