I’d argue that parents are different to a ‘leader’ as we perceive them, or as I read was suggested in the comment. Children will stick with their parents, up to the point at which they’re ready to start their own family, like you say, but is that leadership in the same sense?
But yes, I agree, pack = family is accurate.
Dogs don’t need a leader - the whole alpha male wolf thing has long been disproven, by the original author none the less. Dogs are highly social and live in groups, yes, but there’s no boss dog. Very few animals have a concept of a leader. In fact I’d argue that none do and it’s a totally human idea.
I like your cat/dog thinking idea though. Cats very much think ‘me me me’!
Is that leadership or just breeding and/or social dominance though? Do they tell others where and when to hunt e.g.? I’m not so knowledgeable about seals of any species so a genuine question.