If I understand your question right, you're wondering (as an example) if bench coaches and pitching coaches influence hitters? My take on it is that pitching coaches have almost no affect on hitters, because their ratings in those areas are generally extremely low. Bench coaches may have some affect on every player, because they can have high enough ratings at hitting, fielding or pitching to help players develop. Apparently though, no one has any idea just how much they contribute. I suspect that all coaching has a much smaller effect than we are led to believe.