I am not a western hunter at all, but I do nerd out pretty heavily on arrows as I build my own. Here is my quick advice followed up with my "2" setups
FOC matters and doesn't matter. There is such a thing as too much and maybe not enough. I believe the ideal setup runs around 13-16% FOC.
FOC has really came into play from interweb knuckleheads that follow Dr. Ashby and live and die by his word (I was once this interweb knucklehead)..But here is the truth, we are not hunting dangerous game with armored plates on their sides. We are hunting whitetails, elk, etc which are pretty "easy" to penetrate.
TAW (Total arrow weight). I have shot very heavy arrows and the one thing I will tell you about a heavy arrow is it definitely quiets your bow significantly, but that IMO is the only advantage to a heavy arrow. What I believe a guy or gal should do is get the heaviest arrow you can while staying as close to 300 fps as you can. This is going to be dependent on draw length, bow poundage and draw weight. I am not saying that everyone needs to shoot 300 fps. Someone with a 26" draw is going to have a harder time getting to 300fps compared to someone shooting a 30" draw. So here are some examples; if you can only shoot a 60lb bow and your arrow has 14% FOC then you may only be able to shoot a 410 gr arrow at 268fps. (All those figures are completely made up). Then this maybe be the heaviest arrow that you can shoot the fastest. My point is that you are achieving good FOC and good speed at the heaviest arrow you can shoot.
Speed used to be something we cared about way back in the 90's and early 2000's. We shot light arrows with over-draws and all sorts of gimmicks to obtain more speed. Now we are in the fad of shooting 12lb arrows with single bevel broadheads. Whats right? Hell, I dont know. All I can tell you is what I believe. Because at the end of the day whether you are shooting a 350 grain arrow or 550 grain arrows if you shoot the animal in the heart it will die, quickly.
I am a firm believer in shooting over 300 fps and here is why. And this is especially for the western guys but not to discredit its importance in whitetail hunting as well. A flat shooting arrow is far more efficient than an arrow that is "lobbed". Also, the pin gaps shrink making quick decisions easier. And the obvious one of string jump which is far less with a faster shooting bow. I am also ok with shooting a whitetail at 50 yards because our equipment is so much for efficient than it was even 10 years ago.
I had my rotator cuff put back on back in May, so I was forced to shoot a lower poundage bow this season so here was my setup:
60lb bow
30" Draw
478 gr TAW 250 spine Sirius Orion
14% FOC
I will be going back to:
80lb bow
30" draw
478 gr TAW 250 spine Sirius Orion
14% FOC
These are just my opinions. I have shot several arrows over the past few years, but I am firm believer in micro diameter arrows to reduce wind draw as well as the drag to push through an animal.
I also believe that people need to start practicing shooting differently. STOP trying to shoot every deer in the heart, stop hugging that shoulder. Shooting 3" behind the shoulder and shoot for lungs. It is equally just as effective and will keep you from hitting the shoulder. I once cared about hitting a deer in the shoulder, but no more. I aim lungs 95% of the time and never have to worry about blowing through a shoulder. Learn proper shot execution and you will hit your spot every time.