Hadda lot to do with the use function and available material Fletcher. So yes sir you are correct.
You find alot more shorter plains style bows where bison were hunted and horse back archery was more common. you find both longer bows as well as arrows where more ground ground stalking and stationary prey or shots were common.
I honestly believe head size THEN was the same as head size NOW.
And as Ron is a fella thats can vouch on penetration power on game as well. If memory serves me Ron won world titles shootin bows in the 100# range. and I also know he's killed big game with bows under 55#s. thats some HUGE draw wieght/BH arrow combo and set up differences there.
I truly love BIG snuffers and ACE 200gr supers. but you won't catch me trying to kill deer with them on a sub 50# bow, lower performance bow, or light wieght arrow. My favorite set up for that is a 60# curve, and a twig thats gonna come in around 580-600grs when tipped with a 200gr ace super express.
Lighter bows?? I'm a WW fan.
Science has 1,000 differnt formulas and methods as does physics to explain to man how penetration works. But in good ol boys terms?? A bowlin balls gonna knock a bigger dent than a soft ball, and it's easier to punch a needle through a hey stack than a shovel. So way before physics proffessors and scientist were here to explain to us all how broadhead size and shape as well as arrow weight and energy placed behind such arrow effects penetration..... I gotta good notion the natives already knew that.
The seminole one fletch or (two fletch as many view it) is one of the main two feathered arrows people see and why it's brought up in most conversations. in all acutality the seminole two fletch was actually a "one fletch"
The reasoning was simple... the best and most available arrow material in their area was cane. They merely SPLIT the nock end of the cane... slid a turkey feather in to the split where it's "fletches/fibers" were evenly disperesed to each side and wrapped it in with sinew.
I spent 4yrs in england and while there read up and talked and visited as many places as I could to learn of the english longbow.
The length and draw wieght of these bows were two fold... you can NOT get that sort of draw wieght out of that design out of the woods they had available WITHOUT the bows being as "tall as a man" Their beliefs were heavier draws helped penetrate armor and lengthen the cast of the shaft. In all effect an arrow will kill as far as you can shoot it. Anyone willing to stand in the middle of a field while someone lobs arrows at them from 150yds away to prove that false?? I'll run the video camera.
Just rambling a bit.... BUt both steer back to materials available. as well as function... Bodkins were designed to penetrate mail armor... we find native heads we call "bird points" merely because they're small..... I would venture to bet smaller heads were for harder to penetrate animals.....
From what I've gathered in my readin the only difference was native american (especially those hunting bison!) were in all reasoning NOT trying to kill their game with a single shot..... It was simply a "shoot it til it stops twitching.... if it runs too far track it down and shoot it again."
Arrow lethailty?? You ever see the test where a 5 gallon bucket is filled with wet sand?? You can put a 600gr shaft with a razor sharp 2 blade off a 70# recurve COMPLETELY through the bucket full of sand... on the other hand..... my 45 acp loaded with 230gr hydra shocks WOULD NOT get an exit hole on the bucket. I know I know force of momentum and penetration compared to ballistics. tomoato potato....... but it shows the stick can do it's job.