If its BB and Imu, imo they will surely be stronger than Kaidou in most aspects. Regarding Shanks, since his CoC is hyped the most, i think Luffy vs Shanks is gonna aim for Luffy surpassing Shanks CoCapplication-wise. Now Akainu, i dunno about this. The more i see Luffy vs Kaidou, the more i feel that the one that face Akainu shouldnt be Luffy, be it from powerscaling or narrative stuff.