I agree with the first half of the scope, but I'm not sure about the second half mainly because it seems like we are limiting the questions to only address a certain part of the sport (rules, regulations, practices, minutia) and not other parts of the sport (training, physical activity, technique).
The F&N FAQ has the following:
Fitness - Stack Exchange is for fitness professionals, athletes and trainers. If you have a question about
improving your exercise performance or technique
choosing a training program
nutrition as it relates to exercise
gear and gadgets used during exercise
achieving physique milestones
This to me sounds more like the physical activity questions suited for F&N are more along the lines of physical fitness, physical training or just general exercise which is different than questions about the physical techniques used in a particular sport. For example, I think that this question would be off-topic at F&N and should be on-topic here:
Difference between one gap and two gap techniques for defensive linemen
I think that both of these can coexist on the same site, but we just need to make a clear distinction between fitness for the sake of fitness and training for a particular sport.
Here is my proposed revision to your original scope:
We exist as a site to ask about the rules, regulations, training and techniques surrounding sports. Questions about physical fitness and general exercise should directed to Fitness & Nutrition.