I'm sure there are a handful. Tim Kennedy and Brian Stann are examples. I was in the Marine Corps and was also a martial arts instructor for their martial arts system and let me tell you, its pretty laughable, at least when compared to other martial arts like Bjj, Muy Thai and boxing. Don't get me wrong, it has its place, but its very watered down, as stated by others. Most guys that transition from the military to high levels of MMA generally have more extensive experience in outside martial arts. Simply put, military training is far different than martial arts training and doesn't transition over, like i said, unless they have outside experience. In fact, its very rare that guys that are in the military really do much other training aside from what their job entails. Generally, martial arts and hand to hand combat in the military, at least from my experience, is something to keep the guys occupied when they have down time. 99% of the training they are doing is field op driven, where they basically train to close with and destroy the enemy with firepower, not hand to hand combat.