I believe that most NA hunting bows were relatively light draw weight, in the 45# range or less. Some did have bows reaching 100# but they were more for war time I believe. The way and reasons they hunted and the way and reasons we hunt are totally different. Today we are more ethical with our hunting and I'm not saying NAs were or are not ethical. They hunted for survival and we hunt for sport.
You can kill any animal in North America with a 45# bow but most opt to shoot a bow as heavy as they can to narrow the chances of loosing a wounded animal. Shoot what is comfortable you you to shoot under all conditions. Good shot placemrent with a well tuned arrow and a very sharp broadhead are more important. IMO.