With NVBIII in the late stages of production, I've been working on an outline for my next significant quest mod, Sinners and Slaves. In a nutshell, it's The Dirty Dozen meets Spartacus (Kubrick version, not that recent drivel). There are two separate questlines in the design doc (one NCR, one Legion), but right now I'm focusing on the NCR perspective.
My chief concern is lore-plausibility in staging a slave revolt in the heart of Arizona. When the Courier arrives, it's little more than a band, but would soon expand into a full-fledged army with a... tragic end (inspired by the Third Servile War). However, I merely want to capture the essence of certain historical figures and events and make it workable in the scope of Fallout. This revolt will not change the fortunes of Caesar's Legion in the end - it might even strengthen them, in fact.
Additionally, I'm concerned with how to depict civilians and non-military settlements within Arizona. JE Sawyer's discussed this on Formspring and Somethingawful, but I want to get it right and avoid any egregious missteps. I see them as functional, secure communities with food and running water, possibly overseen by a handful of Legion troops and/or administrators. There would be a greater military presence in towns like Kingman, and certainly in and around Flagstaff, it being the capital.
Finally, the question of how a revolt could start looms large. My current treatment suggests that two recently-captured tribes were driven to the center of Arizona by an incompetent, mid-level commander (Caesar and Lanius can't be everywhere), and were rushed into service without proper assimilation. Specifically, the commander thought it would be sporting to pit the two tribes against each other in the arena (in small groups), with the survivors being "rewarded" with military service. At some point, the tribes rise up and overwhelm the troops supervising them, then head to the wilderness of Humphreys Peak. This is where the Courier finds them.
Maybe the basic premise is just too far beyond the pale - if that is the case, please tell me. Nitpick, suggest, and/or dissuade as you feel. Thanks for any forthcoming feedback!