Here's the mob counts to look for when requesting each adventure for the various zones:
Deepest Guk Theme (South Ro)
58 = Mushroom Grove
57 = Ancient Aqueducts
56 = Chapel of the Witnesses
56 = Foreboding Prison
55 = Root Garden
54 = Drowning Crypt
53 = Cauldron of Lost Souls
51 = Accursed Sanctuary