pdk25 is right, there is no one answer for that question. There are too many variables in bow design. In reality, if you shoot all 3 lengths equally well, I doubt the performance difference (if any) would be enough to notice. If I were you, I'd shoot the one you are the most accurate with. The most efficient bow is the one you can shoot best. If you miss, you can consider all the energy put into the shot as wasted. I can appreciate that you like learning all the technical stuff, but with trad hunting most of that doesn't make a bear's turd worth of difference. Your hunting skills and shooting ability are 95% of the game, the bow is only about 5% of success. Focus on the 95%...