Leopard, tiger, buffalo, wild boar, black bear, which one does not belong to the same category as the others?

Taxonomically speaking,

Leopards and tigers belong to the family Mammalia, order Carnivora, order Feline;

Buffalo belongs to class Mammalia, order Artiodactyla, order Bovidae;

Wild boars belong to the family Mammalia, order Artiodactyla, order Suidae;

Black bears belong to class Mammalia, order Carnivora, order Ursidae.

Can't find any different types.

In terms of living habits,

Leopards and tigers basically only eat meat;

Wild boars and black bears are omnivores;

Buffalo Just eating grass is not in the same category.