Scent vs sight hounds, over 30 years training every group and 100's of breeds, the scent hounds & terriers take more time & patience because they're easily distracted by their noses. The schooling environment is critical with the early stages & building confidence.
The sight hounds are more difficult to generalize, such a wide variety of "personalities"
Andrew pretty sure Costello is just resource guarding his gravy train, now the Dutch Shepherd is a dog that lives for you & won't hesitate to lay his life down to protect yours.