For one thing, I'd be willing to bet that their coats would be a bit more manageable! Because no one in their right mind would want to try and maintain those insanely thick coats all summer long during water rescue training and testing!
True. Cole's coat is actually very easy to maintain because he has about 1/2 as much as many Newfs in the ring. He FINALLY got rear feathers that reach his hocks...at the age of 3. His body hair is sleek, short and correct. He does have a lot of chest hair and front leg feathers (he's such a manly-man LOL), but all in all his coat is perfect for swimming. It dries pretty quickly too...unlike some of our others.
His head, however, is more of the "newer", more typey style. He can swim well, and retrieve well, and is STRONG in and out of the water...so now all Momma has to do it get him out there. How I wish there were some people to train with locally. They're far and few between around here.
Conditioning makes a huge difference too. That cannot be empathized enough. So many dogs only get out to run and swim intermittently or on weekends. Even those without excellent natural athletic ability do much better when they're "buff". They NEED to run, and play, and swim, and run some more, every day. Having lots of dogs helps us keep ours that way. Even Molly, who is quite the couch potato, gets out every day and races around and around. She has other dogs keeping her motivated. But if there are no other dogs...humans need to do it.
A dog can't be expected to swim for hours retrieving items...haul a boat...haul a person or two...without being in shape.
I suspect many "can" do the job, no matter what their "type" is, but some just don't have the conditioning needed to do it. Granted, to some it's natural, and they have the innate drive, but they still have to be in excellent condition to do it.
I believe the intense "drive" is genetic, as is the ease of doing the job, but I also believe that as long as there is a desire (and the dog MUST like doing what it's doing), and there aren't any serious structural issues, if a Newf is conditioned properly ... it can do what's required. Maybe not spectacularly, or for hours on end, but many can achieve those working titles.