I would think that one of Claude Van Order's triangular points, on a tonkin shaft, would penetrate quite well, or even a narrow wedge shaped, and tapering thickness from the point to the back would also be the trick, made out of some cowboy's hard Texas rock. As for reliability, of the attachment of the head, it is reliable. When you can shoot through a big ol hog from a angle, and pass through the hip, and lodge in the opposite shoulder bone, I would think it would hold up quite well. Just do as said and wrap it well, and smooth the transition to the head. I have complete confidence in a stone head. That boy "is" rather well armored. But I don't see the ribs being any thicker than a cow, or an Elk, just a lot wider. So I still think that a good stone point will penetrate, and slice and dice. As for wounding, carry extra arrows of course, and a back up. .45/70 .416 rigby, .458, .375 etc. But I really don't see penetration being a real problem with a good stone head. I am sure Claude can come up with a good design. He is definitely a master knapper.
Wayne