They patrol literall space wastelands where dust raiders just vanished and nobody knows where they are. They supposedly already got one engagement that damaged their ship and nearly exhausted their supplies, yet they still fly in a space coffin instead of going back for re-arm and repair. They are guarding Tychon's Rift, sector that CLF activity is high. The same sector where battalion of UPP hungry for American blood is stationing. Sector full of pirates (vessel that hit prison station) and freelancers ready to pop a bullet in your head if someone pays enough. And with recent "test" also a probable spot of Beno-Breeding.
Yeah, I wouldn't call guarding this sector as "suicidal". It's walk in the park in the reality. All those firendly factions and very nice alien specie that likes to be petted.
It's not officialy a penal battalion, but it has basically every quirk of one. Alien, or Predator, or Real Life "lore" of Hamburgerica won't cover this.
"The last several years almost a dozen worlds have gone dark, and several USCM detachments and garrisons have seemingly disappeared. Recruitment to the USCM has sharply dropped, and morale has plummeted, especially among the outer-rim colonies that depend on the USCM for protection from pirates and hostile nations."
You won't find in modern day examples where private company exchanges tech and supplies with govts (and military) for safety of their own colonies, yet we have WY.
Also this: https://en.wikipedia.org/wiki/Felony_waiver
There is nothing too far fetched about govts loosing up those "waiver" requirements for more serious crimes when manpower goes really low and criminals are at hand's reach.