I'm being general as I didn't list all pets but I'd say that's a pretty good trio of pet types and pets usually within the groups. It is indeed general and not exhaustive.
Parrots and monkeys are group 1, for example. Rat and budgie are 2. Spider and lizard and tortoise are 3.
Sea monkeys transcend all groups and break all rules.
I'm well aware. It described roughly the same amount of food as a 3 course meal for 1 person, with drinks.