yeah none of the factions are finished(or barely even started) in terms of uniqueness yet, the legion just have a UU that clanky added.
The arena could have that ability as an improvement, but not a building.
can't do the manufacturing plant effect.
Eventually the raiders will have a bunch of deniable Op units to go well.. raiding like crazy. They will also get some cheap DOp vehicles ala mad max style.
I also want to have different 'raider affiliations' with their traits, somewhere someone had written some stuff on the different raider groups and what benefits they might have for the player.
Their will also be some differences in the benefits of slaves between factions, but haven't got to that yet either, or entirely decided what the differences will be.