I think a 2 blade cut on impact blade would get the best penetration. Recurve shooters typically get less kinetic energy (heavy arrow lighter poundage = less KE) that is why this design has prevailed with that equipment. I shoot 2 blade Ace broadheads in my recurve and use 3 blade Thunderheads with my compound. Using a 40# bow you want as much penetration as possible, you get that with a 2 blade.
Bill