Bear in mind, as the Ogres are part of the Kingdoms of Men list, that your base force is Neutral, so it doesn't matter which other models you pick, as they can ally with either Good or Evil.
Goblins is the only real Horde army, although, you could avoid it with lots of Mawbeasts.
Orcs and Undead, whilst traditionally Horde armies, can be filled with lots of cavalry (breaks away from the Large Infantry Ogres) or elite units like Trolls, Werewolves, Wraiths and Wights.
Oh, and there might be an Ogre list released around the same time as the models. But I didn't tell you that...