If thats the case and thy group tight , and you can see your arrows fly straight , they must if they group . Id do the same thing . I think you will find that 2 blade heads will group well allso for you , and probably closer to where your field tips are hitting . One thing to keep in mind , with the field tips and broadheads hitting diferant spots is , to keep your 2 blade heads orinted in the same way arrow to arrow , all vertical or all horizontal , try both ways and see iff it makes a diferance . Just a guess but Ill bett for your setup that a horizontal orintation will give you the best results .