Force with these kinds of dogs can lead to a dog that will push back. Unless you are willing to handle an angry 140+ pound dog coming up the leash at you for what was considered a hard, unfair correction, then understanding and leadership are the way to go. Some LGDs are not that food or play motivated, like some Chows I have encountered. These dogs can redirect in a similar manner to a Rotty, if you have ever handled a hot one.