Longer arrows will close your gap and because of that you will shoot better at hunting ranges regardless of whether you shoot instinctive, gap, split vision, etc...
I had a lot of trouble tuning carbon arrows, back when we first started shooting carbon with our trad bows many years ago, until I left my arrows longer. I like to shoot around a 31.5" arrow with a 200 grain point and don't worry about the rest(FOC, etc..). A 500 spine arrow, with the 200 grain point and 31.5" length has been very easy to bareshaft tune various bows in the low 40's to around 50 lbs for me, and usually ends up around 500+- grains in weight....
This combo has been very effective for whitetail deer, hogs and turkey - and I've done very well shooting 3D with this arrow also..