guts of iron are ogres chosen by a Tyrant as his personal bodyguards. Though not necessarily any tougher or stronger than their fellow ogres, the simple fact of being chosen gives them an intractable belief in their own superiority, amplified by the respect given to them by the common Bulls
As the Tyrant's bodyguards, Ironguts have the best wargear, fighting with the large two-handed clubs, giant scimitars, or young tree trunks reinforced with stone. They can also afford heavy armour, which generally consists of large chunks of enemy armour hammered together. In a rare display of hygiene, some of them will even wash it out! The Gutlord and other powerful individuals might have custom-made armour, as befits someone in their position
As their name suggests, Ironguts are capable of ingesting almost anything, the only Ogres that can beat them at that are the shamanistic Butchers and Slaughtermasters. The leaders of Ironguts must also excel at this, for otherwise they wouldn't be known as Gutlords