It certainly could have been done IF the various tribes and confederations had been able to overcome millinea of mutual hate and distrust of their neighboring tribes and confederations.
Somehow I doubt that could have been accomplished though.
It actually came fairly close. The tribes all recognized the danger. It wasn't so much their mutual distrust and hate that got them, it was that they had differing ideas on how to deal with the white threat. Some wanted to fight to the end, some always wanted to move west as long as there was land there to do it, and some wanted to try and live in peace with the whites and not move. Usually, they would unite and then a defeat or a setback would fracture the coalition. Just another victory or two here or there would have gone a long way towards cementing the various confederacies that arose between the Indians.
