Ed ashby has don't extensive test on bow and arrow performance for hunting and he what he found was people assume the arrow cuts more if it stays inside but it doesn't, it's just false speculation. Same reason if you have a stab wound they tell you NOT to pull the object out to reduce bleeding until you can get help...just because a guy in a video claims something to be true doesn't mean it is, you need data to back up a hypothesis.
I believe he was speculating on the reasoning of the Indians of the period, right or wrong, rather than stating it as a fact, though it seems to be his personal opinion as well.
He also pointed out the difficulty in getting adequate accuracy with that type of warbow due to stability at full draw. He found his aim was shaky at full draw with his replica. Not everyone can get good accuracy with that heavy a bow.
Modern bow hunting regulations suggest a minimum of 40# draw weight at 28 inches which suggests this is considered adequate for deer at most eastern woods hunting ranges. 80# would be better only if you can get good consistent accuracy under hunting conditions.
The longer war bow would be less forgiving in snap shooting and shots at running game or firing on the move according to his testing.
The Comanche preferred a very short bow with short draw for its manuverability, especially on horseback, and rapidity of fire rather than maximum power.
Those indians prefering longer bows seldom used horses in war.
The long warbows of Indians in Florida could shoot through two layers of Spanish chain mail armor, so they definitely were very powerful bows.
On the other hand some east coast tribes often used very light bows around 25# draw in war, depending on pinpoint close range accuracy rather than power, Shooting armored men in the throat, though they did have more powerful bows for hunting. The arrow heads they used were tiny compared to others I've seen.