I'm interested, but as a long time fallout fan, I have to say this wouldn't work. It's been shown that if a tribe refuses to join, Ceasar uses superior equient and formations and simply throws an entire legion of thousands of men to crush even the smallest tribe. I understand if you want some kind of alternative timeline, but the tribe wouldn't actually last a week.

This aside, a story of futile resistance could still be good. The only tribe left alone, temporary as it was, was the New Caananites. A tribe of 185 total would have to split it's home and resort to guerrilla warfare, which in it's own way is tempting.