Oh hey I modded this game.
I think the strongman/ninja existed to work with the PT cop's complex modifier but it is a weird choice to include those roles without protectives or motion roles respectively. I didn't design the setup, but if I did I'd have probably just made them visitors since it's technically a PR, albeit a useless one, thus would be detected by the PT cop.
I thought the setup was fine otherwise although the reviewers said it was townsided and I'd have to agree with that.