My Cooper was easy to train BUT I am home with him all the time. I took him out every 2 hours and said go potty. I now have to walk outside with him every time he goes. If I just open the door for him to go outside he will sit there and wait for me to come out. I am trying to break him of this because it is getting cold here and I don't want to go out and stand in my pajamas.
On the other hand if we go to other peoples houses he will mark at their house so I put a belly band on him. We are working on that bad behavior and you are right it is hard to break.
I find that when we go outside that he has to smell, smell, smell then decide to do his duty. Watch and be patient when he is outside and you will see they do the same thing every time they are ready to poop.
Now that it is cold he will pee and then think he is going to come in, I pick him up put him back on the lawn and say I know there is more and then he figures out goes and runs back into the house. Dogs will poop at about the same time everyday. If you know when that time is you can kind of control it.
Best of luck in training be patient, and consistent, they like a routine I'm sure he will come around.
Celeste