My first, Max, had an 'only child' personality and would have been great on his own. We had an encounter with a couple of loose Yorkies and he enjoyed them, so we went and got Max's brother Teddy.
Max was a little over a year old and Teddy was 8 months when we brought him home.
They do not self-entertain (still want their humans for everything
), but they definitely enjoy each other.
It's double the vet bills and grooming, but double the pleasure. Best wishes!