I just find it hilarious and honestly quite badass that Sanji has tuned his Kenbunshoku Haki to the point where he can pick up the slightest signal of a female in distress (within his range). Whether it be Tashigi on Punk Hazard when she was overwhelmed by Vergo and he heard her tears fall, or knowing Viola's true self upon gazing into her eyes even though he was beaten bloody by her, or realising the lies Pudding was supporting her reality with once looking into her third eye. When it comes to females, Sanji can do what no one else in the One Piece world can - understand when a female is in anguish/uncomfortable even if hidden behind training, hate or lies.
The fact that Sanji can hear what the two strongest Straw Hat Pirates cannot is proof of how insanely godly his Kenbunshoku Haki is in regards to females. Honestly, at this point, I don't think any female can fool Sanji now (unless he wants to be fooled), especially if he looks them in the eyes and gazes into their soul. The scenario playing out in the situation Sanji is overhearing is definitely something that would trigger his attention/Haki - lewd actions toward a female. With his curiosity and "chivalrous" nature awakened, there is no way Sanji wouldn't investigate that area even if it involves splitting off from Luffy and Jinbe.
There is a limited amount of characters whom the person being perverted with the female can be, especially if there are an enemy of the Straw Hat Pirates. Aside from Orochi, I can't think of anyone else. All the Tobi Roppo are preoccupied with the war (or singing in Black Maria's case) to engage in such debauchery. If Orochi is alive, there appears to be only two ways for him to survive; either through his Devil Fruit or through an Ink-clone created by Kanjuro. If the Yamata no Orochi devil fruit did save Orochi from Kaido's attack, the reaction would been noticeable after the beheading. Seeing as Orochi has been forgotten within the current chaos, this leads to me to believe that if Orochi is alive, it would be because of Kanjuro using an Ink-clone to stand in for Orochi. Such reasoning can explain Orochi's current actions and being unaware of the current events. It would also explain why Kiku ended up overpowering Kanjuro. Upon Kanjuro's ink-clone being destroyed the reaction within Kanjuro at having his attention diverted would have created an opportunity for Kiku to cut him down. Or Kanjuro let himself be cut down knowing there was no point in continuing to fight with Kaido having betrayed the Kurozumi clan. The ink-clone would have dissipated unnoticed while everyone's attention was directed to Kaido's speech and the response of Orochi's subordinates.
If that character is Orochi, I see no issue with Sanji encountering him now. Once Orochi is informed of what happens (likely by Fukurokuju as Kanjuro may have trouble navigating through the mansion), he will retreat and likely use the battleship he procured from the CP0 to attack Wano Kuni/Onigashima. Ultimately, once cornered, Orochi will unleash and Zoro, Hiyori, Yamato and Momonosuke will have their moment.
As for Law, he is the key to defeating Kaido.
Croc or Enel would never.
At least they provided good entertainment and kept threads alive through a couple of months, which was particularly fun during the last batch of cutting and skipping annoying chapters.
