Matt,
I agree that such giants would have been different; humanoid, but not fully human. Common descriptions of giants in different geographical locations include red hair, double rows of teeth, six digits on each hand and foot, and generally cannabalistic behavior. Supposedly there were Native American tribes who fought against them. I've even heard about some Alaska natives describing giants in the past. Those are pretty distinctive descriptions to come from such a variety of disparate places and cultures on the earth.