Yeah you won't gain much (if at all) if your displayed skill is more than 20 pts different than your target's wrestling skill. So Trog's won't be good till get your skill up to 70s.
I would suggest you goto New Haven and buy skill from fencing instructor, that will get you a flat 40 to start off.
Then I would work Lizard Men till about 65ish. Then can do harpies/earth elementals or Trogs for a while, those should get to 90s well. Can continue to beat on Trogs after that but gains will get slower and slower, so around 100 could go beat on some Tuski Wolves or Yomotsu Warriors, or the ole Ogre Lords which will take you to 120.