Here's some interesting things that J.E. Sawyer himself had to say on the Legion.
Edward Sallow created Caesar's Legion as an imitation of the Roman Legion, but without any of the Roman society that supported the Roman Legion. I've written this before, but there are no optimates, no populares, no plebes, no equestrians, no patricians, no senate, no Rome. There's no right to private property (within the Legion itself). There's no civil law. There aren't even the ceremonial trappings of Roman society. Legates don't receive triumphs following a victory. No one in the Legion retires to a villa in Sedona. Soldiers in Caesar's Legion don't have personal freedom. They "get" to fight and die for Caesar. It's not a volunteer military, though many legionaries are born or raised into it, so they are effectively brainwashed. It's essentially a Roman legion with only the very top commander having any connection to the "source" culture, the rest being indoctrinated conscripts from cultures that were honestly less well-developed than anything in Gaul. Gauls are pretty sophisticated compared to the 80+ tribes. Gauls could read the Latin or Greek alphabets (Gallic language, obviously), had extensive permanent settlements, roads, calendars, mines, and a whole load of poo poo that groups like the Blackfoots never had. What Caesar gave to those tribes was order, discipline, an end to internecine tribal violence (eventually), common language, and a common culture that was not rooted in any of their parent cultures. The price was extreme brutality, an enormous loss of life and individual culture, the complete dissolution of anything resembling a traditional family, and the indoctrination of fascist values. Caesar's Legion isn't the Roman Empire or the Roman Republic. It isn't even the Roman Legion. It's a slave army with trappings of foreign-conscripted Roman legionaries during the late empire. All military, no civilian, and with none of the supporting civilian culture.
The additional Legion locations would have had more traveling non-Legion residents of Legion territories. The Fort and Cottonwood Cove made sense as heavy military outposts where the vast majority of the population consisted of soldiers and slaves. The other locations would have had more "civilians". It's not accurate to think of them as citizens of the Legion (the Legion is purely military), but as non-tribal people who live in areas under Legion control. While Caesar intentionally enslaves NCR and Mojave residents in the war zone, most of the enslavement that happens in the east happens to tribals. As Raul indicates, there are non-tribal communities that came under Legion control a long time ago. The additional locations would have shown what life is like for those people. The general tone would have been what you would expect from life under a stable military dictatorship facing no internal resistance: the majority of people enjoy safe and productive lives (more than they had prior to the Legion's arrival) but have no freedoms, rights, or say in what happens in their communities. Water and power flow consistently, food is adequate, travel is safe, and occasionally someone steps afoul of a legionary and gets his or her head cut off. If the Legion tells someone to do something, they only ask once -- even if that means an entire community has to pick up and move fifty miles away. Corruption within the Legion is rare and Caesar deals with it harshly (even by Legion standards). In short, residents of Legion territories aren't really citizens and they aren't slaves, but they're also not free. People who keep their mouths shut, go about their business, and nod at the rare requests the Legion makes of them -- they can live very well. Many of them don't care at all that they don't have a say in what happens around them (mostly because they felt they never had a say in it before the Legion came, anyway)."
So let's just summarise: the Legion is a slave army. It's people don't have any rights and are basically subject to the whims of its rulers. You fight until you die and you don't get a say in anything.