No ninjas, they're much to cliche and hard to control, as well as somewhat tacky. Plus, they can almost never work well in the day or against a large fighting force. Perhaps there should be a deadly and efficent european-style fighting force composed of a light horse regiment and several of foot, or a large array of guerillia units, ready to spring into battle, fluid and undetectable. Imagine the dragoons, rushing in there on horseback and taking out whatever force the Von Helsons have at their hands--It'll be the southern campaign all over again.
Besides, I'm sure that everyone else would love to participate in a battle, why leave it to only a few people?