Two things determine sight pin gap: bow speed and the distance of the sight pins from your eye. The pin gap increases with the distance from your eye. The sight pins also appear smaller. The pin gap will get greater at longer distances because the arrow will fall faster as it slows. Some sights have sight pins that actually touch. That can be a disadvantage because the sight pins obscure the target. The target is what you are aiming at and need to see. You can’t hit it if you can’t see it. That is why most target shooters with super fast bows use a moveable sight pin. Sight pins closer than 3/16” are distracting. You do not need 2 sight pins in the vitals. In fact, many times that causes people to not pick a fine spot to aim because they think they can’t miss with 2 pins in the vitals. You are probably better off to set your sight pins for 20, 40, 50 yards if you can’t get your second pin close enough for 30 yards. Your 40 yard pin will be in the vitals by the time your 20 yard pin gets to the top of the back.