There have many theories about the devil fruit capabilities of the Red Hair Pirates. Many people in the community believe that Shanks has to have a devil fruit to be a Yonko.
Many other people believe that Shanks does not have a devil a fruit and his entire crew is comprised of Haki specialists with a few exceptions. What if the answer is somewhere in the middle though?
What if Shanks’ crew is composed of devil fruit weapon users or in other words what if Shanks’ crew are Haki specialists who use weapons and gadgets that have been imbued with devil fruits?
Perhaps, Shanks and the rest of his crew decided they did not want to become a crew that relied heavily on devil fruits or lose the ability to swim, so they found out how to put a devil fruits inside inanimate objects and use them to fight. If this was the case, it would explain a few things like why Shanks had Luffy’s devil fruit, the Gomu Gomu no Mi but had not eaten it yet and how he was able to swim when saving Luffy despite being a revered pirate of the New World.
Some might ask, though, what abilities would the crew be able to muster when they rely on weapons and gadgets imbued with devil fruits? To be honest, I don’t know because the anime has only shown weapons that turn into animals. I’m sure we can all imagine a sword with Luffy’s abilities though, or following a popular theory around Shiliew and Jozu, a sword capable of turning into diamond.
On top of that, there are theories that Fujitora has no devil fruit abilities and it’s his sword that has all of the devil fruit capabilities, and if these theories were true that would give an idea of how powerful Shanks’ crew could be with weapons and gadgets imbued with devil fruits.
Although I can imagine Yasopp shooting bullets that turn into animals as well as many other things, there is no way of knowing how powerful Shanks crew could be with weapons and gadgets imbued with devil fruits and we won’t know until we learn more about weapons imbued with devil fruits.
*Theory by Toto27