If bow and arrow are set up correctly I doubt a high FOC will help produce better groups. It is my understanding that the high FOC makes the arrow flighta little more forgiving in poor conditions and really helps with penetration. I know that, from my own experience, my 17% FOC arrows would definitely out penetrate my targets compared to arrows that I have at around 11-12% FOC. I set my deer arrows up with a high FOC for the better penetration it is supposed to provide.