This argument was always flawed. Kaido didn't go for Shanks either, while Shanks in fact interfered with Kaido and sent him home, resulting in Kaido putting him up there with Roger, Whitebeard and Xebec. Kaido also showed big concern about Big Mom arriving, saying they are not prepared for war, yet felt confident claiming One Piece once teaming up with Big Mom and going for the ancient weapons.