I'm thinking of starting a third army and am thinking about O&Gs due to their wackiness. My question is what do they do well? They seem kind of soft with little to no armor and only 4 toughness to make up for it..average stats all around..but they're cheap.

Is that the general idea? A horde army that uses cheap units to swarm the battlefield? Do they have any other perks? What are their biggest weaknesses?