there are different eras chosen by different groups.
I do not know anybody who would consider themselves "Indian Re-enactors"..or who would allow themselves to be called that on a flyer or anything.

I think you're picturing the whole thing a lot nastier than it truly is.
I do Fur Trade Era and I do not pretend to be an 'indian' even though our equipment and skills are Plains based (because that's what is appropriate for this area)