The Steel Gauntlet is a small band of Marines, picked by Admiral Richard Stahl himself, also known as Stahl's Own.
Originally founded shortly after the Ascent, it was briefly disbanded during the Peace Hawk Debacle. After Admiral Stahl returned with the USS Devastator in the first Union-Y'all War it was formally reformed.
While Logistically they are a part of larger commands, their actual command structure is separate from them.
The Steel Gauntlet is the First Company (Alpha Company) of MFRB (deadly gosts)