Witchers will no doubt be a debatable topic. Less contentious/skubish: Monsters!
Here’s a hip-fire series of approximations:
Minions:
Barghest, Ghouls, Nekkers, Harpies, Drowners (Freshwater), Weaker Wraiths, evil vegitation, sirens, Leshen animals, Worker Endrega; creatures that usually are spawned in groups in W3.
Rivals:
Alghouls, Lesser/Animalistic Vampires, Noon/Night Wraiths with solvable curses, Smaller draconids and hybrids, elementals, Foglets w/illusions, Average humanoid Relicts, stronger harpies, zurgals (tentacle things in sewers), trolls, weaker hags, weaker lycanthropes, warrior endrega; creatures that normally are supported by minions, are at most one-shot Witcher contracts in W3.
Nemesis:
“The Exotics” that usually get parts of major sidequests or high-level contracts: Hyms, Leshen, Fiends, Greater Vampires, Genies, Endrega Queens, Manticores, Giants, Striga, Plague Maidens, Kayran, Chorts, Larger hybrids, and stronger/smarter/older versions of the above Rivals.
Campaign Threats/Factors:
Your Gaunter O’Dimms, Detlaffs (Higher Vampires), Dagons (Eldritch Lords), Dryad Queens, and Dragons should be preserved as massive threats. Geralt in-books avoids Higher Vampires because he describes them as suicide runs, and a Dragon takes a small army to bring down.
A good note to remember: just because Geralt can bring down something single-handed does not garuntee the average Witcher can without help.
Edited by Skywalken