I think the animal is dead as dead, even if the arrow doesn't pass through both sides, at least on a good hit. However, it benifits recovery by adding the opposite side hole for a better blood trail should the animal not fall within my sight. As far as a complete pass through that sticks in the ground after going through the animal, well thats just for my benefit, in wanting to re-use an arrow.
Hows that pertain to the subject? Well to explain, I need to inject a bit of info I read on testing done with a chronograph by several fellas over on TG. I will spare details, but in the study, bows from 43 lbs to I think 55 lbs, had very little speed differences. By very little , im talking about 5-6 ft per second between the slowest bow and the fastest when same arrow and same guy was used. Numerous top brands of bows were used, as well as recurves and longbows. In essence....draw weight, make, type, mattered very little and all shot basically the same speeds with the same arrow. So before giving too much credit to higher poundage bows, maybe do some chronographing, and see for yourself. ..... this same phenomenon has been known for years now, but just not believed or acted upon by very many. Fact is, heavier bows do offer more energy for penatration and speed, but its so little difference that it takes high tech equipment to detect it, and its of little benifit. Ashby said as much, by comparing 80lb bow penetration percentages to that of 40 lb bow penetration percentages testing on aisiatic buffalo. His test showed both had the same failure rates with improper weighted arrows, and both had the same successful penetration rates for properly weighted arrows (FOC), which by the way was 100% success rate for both bow weights with proper and identical FOC % arrows......there were no difference between them. Like I said earlier somewhere, the bow is just the energizer of the lethal portion we call an arrow. Change arrow properties, not bow weights to increase penetration. Lighter bows do the exact same job as the heavier bows, but typically more accurately. Any difference you gain by using heavier bows is negligible.
The element of surprise can never be replaced by persistence.