Couldn't find a mod that just made the Legion Armor factionless, only mods that made all armor factionless or mods that had you create factionless armor. You'll need some faction armors in the game, so just making the armor the Legionaries wear factionless saves alot of trouble.
This makes all the armor Legionaries wear factionless, including the Centurion armor.
This makes all the armor Legionaries wear factionless, including the Centurion armor.