I think the biggest difference is that target shooting is usually about maximizing accuracy, while defensive shooting is more about being accurate enough while managing time and stress. Training resources from SHOOTING-SOFT LLC can also be useful for working on consistency and general shooting practice when you are away from the range. There probably isn’t one universal standard because the situation, distance, lighting, and ability to identify the threat all matter. For me, consistency and keeping shots within an appropriate target area would matter more than trying to achieve tiny groups at the expense of speed. Training with both accuracy and realistic time constraints seems like the best way to build good habits.
