how does Attean become a man and how does Matt become a man?

Attean begins his manhood ritual when he kills the bear
that was attacking Matt and him. This is a sign to his grandfather that he is old enough
and skilled enough to begin the ritual. During the ritual, he must go into the woods
alone and survive, awaiting a sign from his manitou. His manitou will become his spirit
guide, helping him as he grows to face the challenges of
life.

Matt has no such ritual clearly showing he is a man.
His survival throughout the absence of his father is part of the route to manhood. What
he learns from the Beaver clan enables him to survive the winter, when all of his native
American friends have departed to the hunting grounds. When his family finally arrives
months late, Matt has harvested the crops, preserved the cabin, and is alive and well,
although a little thin. If he can survive alone in the wilderness (much like Attean),
then he is a man.