ShadowWalker, I have not made a native American style horn bow. It's a project that's on my list though. With respect, the author of the PA article makes it plain in his pamphlet that he recreated the method he uses. (Which is another way of saying he made it up.) His method results in some beautiful and functional bows. But, none of the horn bows I've seen described in museum collections have a wooden core. The originals all appear to be one long piece of horn or two shorter pieces butted or overlapped at the handle. Butted joints had a separate handle piece laid across the back of the joint. Note- the originals had a little set back at the handle. The straight horn pieces will be pulled into a large reflex as the sinew dries. When strung the result is the gull-winged profile so identified with the plains horse tribes. My plan is to stick with the original construction method. Two strips butted together over a short horn handle piece. The originals were riveted! Then the backs were sinewed heavily, using hide glue. The nocks were almost always built up from sinew and glue. Another note is the bows in the museum collections are listed as being made from sheep horn, elk antler and cow horn. Buffalo horn bows were very rare? I'll probably cheat and use either water buffalo or gemsbok horn strips as easier to obtain.
About bow performance; I've seen references to another online group that includes Tim B., Karpowicz and others. These guys are really uber geeks, focused the mechanical engineering side of bow making. Some of their work is really cool and a help in understanding bow design, but millenia of experience show that a bows can be made without worrying about all that. In fact Tim makes it plain in his writing that bows are trade offs. You make a bow based on what you will use it for. Ultimate efficiency ( as an engine) is rarely the first desideratum.
Ron