Yeah, the base humaniods are kinda beefy and hit harder than one might expect. I'm trying to give a 1E feel with large encounter numbers so I'm using no-ability commoners, bandits and guards to represent their rank and file foot troops with the base MM versions with their racial special racial abilities as veterans.
my orcs were in pathfinder though, and their CR was 1/3 according to bestiary. the completely wrecked the pc's.