Hmm, no orcs... where would you get your generic fodder enemy?
And why specifically the half-ogre? Thats even least likely then a half-orc.
Goblins, Bugbears, Hobgoblins;
Gnolls, Flinds,
Kobolds,
Ogres (more intelligent than standard, and very vile...hence half-ogres.)
Bruteman tribes (neanderthals).