This seems interesting- count me in.

Here are a few potential more specific factions (Just spit balling. Wouldn't be offended if you wanted to change things)-

Ozwald- A nobleman with a reputation as an incredibly talented magician. Everyone believes that he can easily destroy an entire army. In actuality, they either can't use magic at all, or only know a few simple and useless spells (Like fireworks or something). Not to mention that they have never been in battle once. Maybe they shouldn't technically be the next one to be sitting in the throne, but not much stands in this "magician's" way.

The Sharpened Blade- A group of rival non-orc mercenaries. Maybe slightly weaker, smaller, or less skilled, but far more trustworthy.

Thomas- The son of the king. No doubt about it, this guy should rule. Only one problem. He's dead. It was obvious that he was murdered, but nobody knows who the guilty party is. 

Isabella- Thomas's sister that is technically next in line for the throne, however, many deem her unfit. She is mute and very young. (Maybe the person the Orcs are supposed to kill? This might make some of the orcs debate whether or not they should execute her- She's just a little girl.)

Archduke Jacob- The most likely to get the crown. The former king's brother. (Maybe the person the Orcs are supposed to kill if nobody likes the Isabella idea. Maybe not a character at all.)

"Slick"- Slick is a conman. He runs multiple illegal underground organizations and has more money than he knows what to do with. However, he's extremely greedy. He would do anything to get more money. Or power. He's very good at deceiving people, however, since most people are familiar with his reputation, they tend to be wary of him. Anyone that knows him well knows that he is a selfish jerk.