IMO, you just answered your own question. There is only one degree of dead. I'm also partial to the "if it ain't broke, fix it until it is" mentality, but in all seriousness, if the load/bullet is accurate for your needs and your game is on the ground within 20 yards of the shot, what's the need to worry?

Personally, I prefer both an entry and exit to leak blood instead of one, whether it's an arrow, modern bullet, or round ball.