Hancock, Crocodile, and Moriah are valuable allies, as they possess fully useful hax (Dehydration, Petrification, Shadow Steal). Moriah could use his Doppelman to try to steal the Yonkous' shadow and put them to sleep, but that would hardly work, as Kaido probably knows his techniques and would alert Linlin. Still, with Law's teleport, the possibility of one of the Yonkous having the shadow stolen is possible, as Law could simply transport Moriah to their backs, and thus he cut their shadow off.
Hancock would also hardly be able to petrify one of them, even with Slave arrows, since the Youkous could deflect the arrows with Haki.
Crocodile likewise would depend on external factors to get close enough to dehydrate someone, which is not impossible with Law on the scene, and that would greatly reduce the chance of victory for Kaido and Linlin.