Well, I am no expert, but I can say that my Rufus is very active, possibly the fastest dog around, but a nightmare hunter. His Dad belonged to a gamekeeper, and his mother was a working pet. He was my first dog, and has been to training and does agility. He had 3 walks a day until 2 years old, when his mad moments reduced to one a day. I am sure I made lots of mistakes in his training. However, his hunting instinct is so strong, catching his first rabbit at 6 months, that I have to use a retractable lead most of the time if I have time constraints. He holds the endurance record for the local maize field- 90 minutes. So although he is very gentle and loving at home, I would go for sofa strain, not field strain!