I understand what you mean now, the 710 is much more efficient at piercing. Like you, a knife is far from my primary defense tool. I have to disagree with you again about the 710 being better for stabbing a mad animal. You are just thinking about 1 stab, and the amount of effort it would take, and not really finishing the thought. Flesh is easy to pierce, and I'm pretty sure we can both agree on that. If I had to be stabbed by one or the other, I would pick the 710 in an instant. The 710 would be a smaller and cleaner wound versus the 810's larger more of a tearing wound that bleeds faster, and is harder to stitch up.
Is 1 stab going to instantly stop the animal? Possibly, but what if it doesn't? What if the first stab hits a bone? The 710 would be at a major disadvantage because it would be deeper in the bone. Not only that, but you can pull out with much more force with the 810 if you were to hit bone.
With that said, I would absolutely choose the 710 to pierce one of those impossible to open clamshell packages. I'm not trying to start a pissin' match, just pointing out that being an efficient piercer may not mean it is always a better piercer. In a way, you could liken it to 9mm vs. .45acp.