Tox, give me a link to that Krabby post; I think I missed it.
Added 1 minute ago
If the Defender can simply be an unremarkable player (sorry if I offend anyone), the Investigator absolutely cannot afford to make mistakes.
It will certainly be more difficult with the last Mafia member, but I think our chances are good.
If we guess correctly and execute Alex/Master, then the second Mafia member is easily identified – Happiness only goes to Nephele or Gumer; there are no other options. It doesn't matter who is protecting them anymore; we mathematically win during the day.