Sights in general are extremely subjective. There is no definitive answer to your question other than you need to simply find what works best for you. As long as you can see your pins and know where they are set respectively.... that will guide you to your mark. They are just a reference point.
Personally, I am a one pin guy. If you have a top pin set at 25 yards.... and most of your shots are going to be 15-25 yards... I think you pretty well have it down. Most shots are closer than that even anyway.