when to train is different depending on the dog. which in turn goes back to genetics-linebreeding.
joey denison introduced his pups at 2 months to a pig. every couple weeks they went back . he documented this very well and if at 6 months they werent getting it done the were a cull. and he only bred the best. thats what made his bloodline so strong. this way has been proven over and over thru the years.cant argue that point b/c it works. so if u have to feed a dog till 18 months just to knowwhetner or not it will hunt. You are already losing time and money. I would consider a different pound or walmart.
So was he just culling crappy dogs, no it was probably just his style of his breeding program. Who to say that those dogs that were culled early wouldn't of been better than the ones that started early. So someone might consider a slow starter for there program normal and other breeder not.
So is it genetics or training