The Combat Engineer advances as a specialist, drawing Primary skills from Savant, Cunning, Brawn and Shooting — the trades of a sapper who opens ground and brings down works. Combat, Ferocity and the Signature set are Secondary; his craft is demolition and the spade, not the drilled discipline of the line.
The Commissar-Quartermaster advances toward control of the line, drawing Primary skills from Leadership, Cunning, Combat, Ferocity, Savant and the Signature set — discipline, close authority and the body-economy of the grind. Shooting and Brawn are Secondary; his weapons are the ledger and the pistol that steadies a wavering rank, not marksmanship.
The Death Rider advances as a mounted skirmisher, taking Agility, Combat, Ferocity and Cunning as Primary — the speed and edge of a lancer who fights on the move. Brawn, Savant, Shooting and the Signature set are Secondary; he is the flank, not the line, and learns the doctrines of the grind only slowly.
The Conscript advances narrowly, if it survives to advance at all — Primary access runs only to Ferocity, Savant and Shooting, the barest trades of a levy fed into the grind. Brawn, Combat and Cunning are Secondary; there is little schooling for a number, and few live long enough to spend it.
The Grenadier is the signature body of the line, drawing Primary skills from Ferocity, Cunning, Savant, Shooting and the Korps Signature set — the disciplined, doctrine-bound advance made a single soldier's craft. Brawn and Combat come only as Secondary; his strength is the lockstep, not the duel.
The Mortar Team advances as a firebase, taking Brawn, Cunning, Savant, Shooting and the Signature set as Primary — the trades of a crew that walks its barrage and hauls its weapon into position. Ferocity is its only Secondary access; it kills from behind the line, not within it.
The Special-Weapons trooper advances toward its trade, drawing Primary skills from Shooting, Cunning, Savant and the Signature set — the craft of the soldier who carries the line's heavy answer. Brawn, Combat and Ferocity are Secondary; its worth is in placing that one weapon well, not in the general brawl.
The Marshal advances broadly, drawing his Primary skills from Leadership, Cunning, Savant, Ferocity, Shooting and the Korps Signature set — the spread of a commander whose work is orders and grinding pressure rather than personal combat. Brawn and Combat come only as Secondary; he directs the line's killing far more than he does it himself.
The Priest advances as a close-quarters zealot, taking Combat, Ferocity, Cunning, Leadership, Savant and the Signature set as Primary — the skills of a firebrand who leads from the point of contact. Shooting and Brawn come only as Secondary; his sermon and his chainsword do his arguing at arm's length.
The Medic advances as a specialist keeper of bodies, drawing Primary skills from Savant, Cunning and Leadership — the trades of salvage, field-work and steadying a rank. Ferocity, Shooting and the Signature set are Secondary; his craft is recovering the fallen, not fighting the living.
The Watchmaster shares the Marshal's officer spread, taking Leadership, Cunning, Savant, Ferocity, Shooting and the Signature set as Primary. He advances as a driver of the line, not a duellist — Brawn and Combat are Secondary, learned only if the fighting reaches him where he stands among the ranks.