Just to be sure, it says that if you're playing with 2 (or 3) expansion boards, the number of investigators is one less (or two less) than the real number.
So if i'm playing a game with 6 investigators, and all boards (Arkham + 3 expansions), I'm considered as playing a 4-investigator game, right ? So if I'm closing the last gate, making 5 trophy gates for my team, I just won, right ?