Whats wrong with no one claiming day 1 and just letting the jailor/gator take a stab at killing? Isn't that the premise of this setp

No it's not. Sam/Jailer claims d1. That's how you know what setup it is. You don't want gator to kill a PR...

I don't know about the overall balance, but interrogator is def. worth more than nilla, jailer is def. worth more than samurai, therefore scum will def. win S2 more often than S1. The same amount of points will be received regardless of which subsetup is played so this setup is def. luckbased.
Thank you for your attention.