There must have been a moment at the beginning, where we could have said no. Somehow we missed it. Well, we'll know better next time.
Are you aware Saboteur 2 is just an expansion for Saboteur.
It depends on which version. I believe the French and Dutch versions DO include the base game, whereas the English, Hungarian and Polish versions DO NOT include the base game.
As for the OPs question. I have only played base Saboteur. Off your list I have only played Bang, Werewolf and Fearsome Floors. I would not say Sabteur's redundant to any of these. It's a fun fast tile-laying psychological game. Definitely recommended.