My theory is just connected to the fact we have 3 captains on the roof top and we have 3 calamities. So I assumed it realistic that each crew is shining though the calamities. Since Jack has some issues with Minks and Inu/Neko, bepo seems to fit best here. It also matches my thought of Luffy>=Kid>Law.
heat and wire are kinda connected to Queen, cause of what he did to Kid and Killer, also he is kinda in dept with the smile fruit.
it just fits.
Also, Heat and Wire, when they appeared in Onigashima, were always pretty confident, calling others asking for help „pathetic“ while slander though the island. Just these two on themselves.
in my opinion, Onigashima is Odas Moment to give the captains and their crews the hype and title they deserve.