In a game with 3 players, Keeper gain 3 threat every turn. On the first turn he summons 3 cultists using Summon Worshippers (1 threat) card, on the next turn he sacrifices them to summon a Shoggoth (3 threat).
This basically means that Keeper will have two shoggoths in both “ends” of the monastery by turn 4. Isn’t it a bit too hard on the players, especially taking in account that there are almost no weapons to be found on the map?