I have shot a lot of deer with my recurves and longbows, mostly with zwickeys and magnus. I have shot the grizzlies and killed about 4 deer with them. Penetration is more arrow flight and shot placement with heavy enough arrows. I shot a 230 pound buck at 35 yards with my 63 pound longbow 2 years ago,540 grain arrow, and passed straight thru. That was with a 3 blade thunder head 125. There was not a single drop of blood. I was fortunate to know the area and I found the buck where he bedded, but had no trail to follow at all. I have shot deer with 2 blades and ruined my jeans tracking the deer because the blood was everywhere, on the brush , trees etc. The blood trail is usually best on the exit side. Since the 2 blade is generally the safest bet on the penetration , if you are not sure go with the 2 blade. I help my buddies with their tracking and skinning,(they are all compounders),and the truth is usually the perfect shot they remember isn,t so perfect once the hide is off and the holes are seen. Be honest about the reality and don't fall into the trap of blaming the equipment for problems caused by poor judgement and misplaced shots. If you get both lungs the deer will be on the ground in less than 100 yards, and shouldn't be that hard to find even with a minimal trail. Some people fall into the trap of thinking they have to get a deer and don't always wait for the right shot. You will be the cause of the success or failure of your hunt, not your gear. Whatever you have the most confidence in will allow you to do your best. OK I'll shut up now.