I think that breeding before 17th century was focused on the dogs job such as hunting wolves (Wolfhounds), sheep herding (Border Collies), watch dogs.
When you don't breed for apperance and only have a low number of different kinds of jobs for dogs, then you only need very few breeds.
The Irish Wolfhounds were out of jobs in 1786 (no more wolves in Ireland) and the breed practically died out.
I think that breeding before 17th century was focused on the dogs job such as hunting wolves (Wolfhounds), sheep herding (Border Collies), watch dogs.
When you don't breed for apperance and only have a low number of different kinds of jobs for dogs, then you only need very few breeds.
The Irish Wolfhounds were out of jobs in 1786 (no more wolves in Ireland) and the breed practically died out.