No-one has said to keep a pup on a lead and baby it til it's 18 months old, all pups need to run around, explore and learn things. I'll have all my young dogs, walking through woods etc, off lead, following me around/through trees, patches of rough ground etc etc. BUT, I wouldn't be entering them on hares until they were physically and mentally ready, which will be nowhere near 9 months old.
Your dogs, do what you like, I just think it's a bit silly and lack of patience entering them on hares at that age, purposely or accidentally. It's easy enough to exercise young dogs where there ar