Just curious, as I have a cocker. Her nose is brilliant. She’s still young so can get distracted but the older she’s getting the more in tune she is getting.
There’s nothing better than watching a dog pick up and scent and track it
I think you had better separate dashing Upland spaniels eg English Cocker, Springer, American Water etc. from the slower heavier spaniels such as Clumber and possibly Sussex that are more closely related to the Basset Hound. you would have to think that the latter would have better ground scenting ability, but that's not to say they can find and flush birds better, as they transparently cannot.