One Shooter One Spaniel One Retriever
I had a dog that was sent for a short retired bird and overran it into the edge of a treeline. Waited a good long time for her to come out of the trees. Judges and I were waiting for her to appear, looking way out three to four hundred yards. After the longest wait in recorded time (at least to me), I yelled at her to "get in here". She popped out of the treeline where she had been sitting for the whole time. I had absolutely no clue why she did it.
The next week she won the Am and qualified for the National Amateur. They are just dogs.
I judged Dewey the first trial he ran after his National Open win. He never picked up the flier. They are just dogs.
So what do you tell a person with a dog who says they want the dog to handle, they have difficulty finding time to train the dog consistently, and they don't want to use an e-collar? Besides good luck, of course.
BTW, I certainly don't look down on anyone who trains sans collar. In fact, I admire you for having that kind of time and for making that kind of commitment of your time to train your dog that way.