I don't agree that dogs are programmed to go long ... or better put, I think whether a dog prefers to go long or short depends
For example, if there is a short gun up - flyer or dead - you will find that some dogs will not want to look past that station or drive past that bird.
In the same vein, sometimes the dogs prefer the long bird because it is more attractive. For example, the short bird is a dinky throw, the long bird is a big throw across the horizon with feathers up in the sun. Depending on the conditions, a long dead bird can be more attractive to the dogs than the shorter flier.
It is one thing to overrun the short retired bird on the way to a long unretired bird.
It is another thing to overrun the short retired bird on the way to the long retired bird.
There are so many different variables that I don't know how valid any generalizations are here.
I never met the man, but I have heard plenty of Rex Carr's students tell me that even though he worked on secondary selection in training that when he was at a trial, if there was an attractive bird that the dogs wanted that was long, he would tell his students to let the dogs take that bird.