In chapter 930 we see the Big Mom Pirates draw near to Wano Country and attempt to scale the waterfall around it, but Kaido’s Disaster King flies in and attacks, causing them to fall into the ocean.
I think it is unlikely that Big Mom was thrown that easily into the sea by King, if not even a bit out of character. I heard lots of people saying that this is exactly what Luffy did and that Luffy also was fine and all I can think of is… EXACTLY. This is what Luffy did. But Big Mom is a very different type of character and mentality than Luffy.
She is a Yonko and has been one for years, she has been a pirate for decades and is very experienced and (excluding Tantrum handicaps) in her normal state she is quite a rational and reasonable actress who is trying to act in her best own interest. It is almost irrational for her to go headfront to clash with Kaido like that, missing 3 out of 4 of her Sweet Commanders, just to face Kaido himself and all of his subordinates in a frontal clash. An enemy she truly sees as equal.
It makes perfect sense for her to go to Wano, this is because she knows that Luffy has copies of her Poneglyph (from Brulee) and she also knows that Luffy plans on taking down Kaido, an enemy she is convinced the Straw Hats have absolutely no chance of taking out. In her eyes, she is about to lose her biggest asset to her main competitor, and that is why she is forced to make her move.
She going to Wano is rational. She going to Wano like this not so much. King himself said ‘what did you think you could do with just one ship?’, and it is indeed odd that the Big Mom Pirates send almost her entire fleet chasing after Luffy, but then to meet Kaido she only grabs one ship, without all of her top Commanders (Katakuri, Cracker, Snack) and hope to somehow get a success.
Even if she had managed to get into Wano like that, would happen next, she would fight Kaido with his forces while Flampe takes out King and Oven deals with Jack?
It is almost a bit unreasonable to assume she would be able to just go head on into Kaido, beat him, then grab Luffy and go back home like that. Shouting at the enemy, making a scene and then charging the enemy head-on just for things to go south right after but still be saved somehow is exactly a Luffy type of thing to do. But not Big Mom.
The Beasts Pirates even said that Big Mom’s intelligence gathering was world class. With all that, is that the best plan they could come up with? I believe there is a bit more to it, and that Brulee is a key factor. Her ability not only allows her to create perfect clones, which is an already established ability that could explain how it is not Big Mom drowning (I am not sure if she could mirror the Mama Chanter itself, but technically it is a living being so perhaps).
I think her ability of being able to transport into mirrors is a phenomenal ability for infiltration, and I think it would be far more in line with Big Mom if she made use of that.
She could go through enemies’ lines and have her and Sweet Commanders enter through some mirror somewhere in Wano silently, this would allow them to penetrate into enemy’s line and would be a move far more likely to increase her chances of success than going head on. Her goal is not Kaido, it is taking out Luffy and recovering her poneglyph. She achieves her goal if she can do that no matter how, and having to go through Kaido and all his forces first in order to do so is a risky move.
My guess is that it is a distraction, and that the real Big Mom will be using Brulee’s ability to sneak into Kaido’s territory to go behind his defense lines (or sneaking it through some other way, like underwater and coating their ships).
*Theory by Dr_Dankology