The infested marine looked a tad bit... uh... too symmetrical, I guess? But I guess its passable because Warcraft sucked at asymmterical models. Ignoring the model being symmetrical, its really pretty.
On the chocobo being too skinny, I would have to agree that its too skinny. Chocobos, while not exactly fat, are supposed to be chubby and fluffy-looking. Which means "get a skinner".
The fallen one's head is kinda messed up, it seems. His body also seemed quite plain without any ornaments except the shoulderguard on the right. And what the heck is that tonfa doing on his left hand?