If we’re talking about livestock, I vote sheep. Truly dull animals.
The dogs on that list aren’t ‘dumb’. They just aren’t as trainable by humans.
My Tibetan Terrier (her breed scores low by that ranking) runs circles around my two obedient mutts. She learns very quickly, but she doesn’t learn to do what you tell her quickly - unless it has to do with really tasty food.
And I would advise most people against a Border Collie. Yes, they are incredibly smart - way too smart for most people, who don’t make their dog their first priority (nothing wrong with that), to keep entertained enough to keep them out of trouble.
ETA: I love a lot of breeds who score lower on that test - I prefer a dog who can think for itself. Not so much into slavish devotion and dedication to performance - like I said, BCs are genius, but a ton of work.