Why one arrow? One of the interesting facets of the carbon game is the difference in arrows--like calibers and bullets. I shoot CE Heritage 250s cut to 28" with a 175 gr. Simmons and a stock adapter from my 58# recurve. I also shoot a FMJ 400 cut the same with a 75 gr. adapter and a 125 point for 3D. In my 58# longbow, I find the 150 CE Heritage left an inch longer, stock adapter and 125 head is all that works consistently.
Bows are like guitars in that the strings work differently for different people. When your fingers release an arrow, it will be different than my fingers releasing the same arrow on the same bow. Carbon arrows GREATLY exagerate this issue. Listen to the guys that tell you to use spine charts sparingly. Test kits are the way to go. Start too long with no fletches and work from there. Once you find a consistent flyer, fletch 'er up and your in business!