Jimmy,

You strangely ignore MASSIVE amounts of data on longevity estimates of natives and, in addition, you strangely ignore MASSIVE amounts of data of longevity estimates of other cultures.

On the latter, there are accurate records in Europe going back hundreds of years, and your odds of surviving after birth weren't good. That is quantitated and curated data from many sources and published in peer reviewed journals by many independent scientists. In the 1600s and 1700s, life expectancy was about 25 to 35 years, in many areas about half of people dying before the end of adolescence.

You want to pretend that, oh, natives of North America, warring in tribes with high homicide rates, were living much longer in centuries prior to that? You are dreaming.

The archeological studies of buried ancient grave remains of natives (Pecos, Tiajinga, Pueblo, etc) tell the story: As in Europe, about half of those buried had NOT reached post-adolescence skeletal maturity. 

Nice try, though...