As usual very nice! As for your Brother.......give him some tools, and some rock, and tell him to go for it.
Like Bone pile said, we all have our own personal favorites. And like Knapper said, the NA's had their own style, and that was what they made. if it worked, they kept it.
As for the Cahokia, is there a reason for the notch in the base, other than looks? Seems to me it would weaken it, as it gives it a third spot to crack or break. As for my favorite style? which ever particular point I can make that looks half way decent, that is my style for now, till I can make a major improvement in my skills. But really nice point there.
Again as usual.
Wayne