The Iron-Grip Phalanx is the most disciplined and militarily capable tribal force within the Caves of Chaos (occupying Cave F). Unlike the chaotic swarms of the Bitter-Bite Skulkers, the Phalanx operates with Roman-style efficiency. They view themselves as the rightful masters of the ravine, maintaining a clean, well-ordered barracks and a standing army of $1+1$ Hit Die warriors who value iron-clad law above all else.
The Phalanx arrived in the Borderlands as a cohesive mercenary legion following a failed coup in the distant hobgoblin kingdoms to the east. Finding the Caves of Chaos to be a perfect natural fortress, they seized the central caves, slaughtering the previous orc inhabitants to establish a "New Citadel." Their history is a series of calculated expansions; they do not raid for fun, but for resources, land, and tactical advantage.
The Phalanx is governed by a strict chain of command:
The Hegemon (Chief): A formidable 5-Hit Die commander (22 hp) who fights with a longsword and wears polished chain mail. He is a master tactician who will not waste his troops' lives on pointless skirmishes.
The Centurions: Each squad of 20 hobgoblins is led by a sub-chief (3 HD) who ensures that formation is kept at all costs. Discipline is enforced through harsh physical punishment.
Security for the Phalanx is professional and redundant:
The Phalanx Wall: In combat, they utilize large shields and spears to form a defensive line that is difficult for low-level adventurers to break.
The Siege Workshop: Their lair contains a specialized armory where they maintain a stock of heavy crossbows and polearms. They are one of the few tribes capable of mounting a counter-siege if the Keep's forces attack.
Guard Rotations: Sentries are posted in shifts; they are never found sleeping on duty. They use a system of horn signals to alert the main barracks of intruders.
Shadow-Stalker’s Syndicate: The Phalanx holds a cold respect for the bugbears' strength but despises their lack of military structure. They often hire the Syndicate for "special operations" that require stealth rather than formation.
The Order of the Iron Bastion: The hobgoblins view the Castellan as their only true peer. They respect the Keep's defenses and prefer a stalemate to an all-out war they might lose.
Other Tribes: They treat orcs and goblins as vassals or slaves. If a tribe fails to pay tribute to the Hegemon, the Phalanx marches in to "restore order."