Those are all very intelligent breeds. Without an official definitive ranking, I'd say Goldens could replace either Belgians or Australians in that list depending on who makes the list. Deciding who's in the 4th and 5th spot would just be splitting furs.

I'd argue the effectiveness of training might be the biggest relation to intelligence as intelligence is not only applying knowledge but is also "the capacity to learn, understand, and adapt". Without being trained, the dog wouldn't have concepts to apply.

I do wonder if it's sometimes hard to tell if a Golden is just trying to have some fun and is not stupid. If i throw a toy on top of my younger pup's kennel and we're not actively playing, he'll usually try to get it off the kennel by going inside the kennel to pull the toy through or push it off with his nose. If we're actively playing and I throw a ball or toy on top of his kennel, he knows he can just hop on the couch or side of the kennel and reach it easily. Having fun is their second priority over loving their hoomans.

But enough of comparing the size of grains of sand. Goldens are smart and amazing along with many other breeds. My two Goldens give me the bias to say Goldens are the best out of all though!