What these breeds have in common
The shorthaired cats are the plush ones: British Shorthairs, American Shorthairs, Exotic Shorthairs, Russian Blues, Chartreux, Bombays, Manx and the ordinary domestic short coat that most cats in the country actually have.
The coat is short but it is not thin. A British Shorthair in particular carries a famously dense double coat with a heavy undercoat under a very short top layer, which is what gives it the plush, crisp feel. It sheds a great deal and mats hardly at all.
These cats mostly manage themselves. What they need from a groomer is help with the volume of shed hair, and that is worth more than it sounds.
What this group means for grooming
Dense plush coats that shed heavily but rarely mat. Deshedding, not clipping.
What actually decides the grooming
The coat type, not the group. It sets the tools, the interval and the price, and two dogs in this group can need completely different appointments.