Ok, the question was more like how N and S can benefit each other practically. If x is unhealthy well, its kinda obvious that getting healthier would improve stuff, hehe, but that's a pretty evident answer and is not practical in daily matters since one can't go around improving healthiness in ppl. I mean, ideally yes, realistically you have to work with ppl how they are and no one is perfect so ego (or communication etc) often makes ppl unaware of how others can improve them or the situation.