Kalran: Tales of the four nations/Frumentarii

"Frumentarii ready to stalk."

Tactical analysis

 * Hidden in plain sight: Intense training and years of experience allows Legion Frumentarii to impersonate any friendly or enemy infantry, granting them access to the most heavily guarded enemy bases. Enemy commanders suspicious of disguised Frumentarii activity must issue a force-attack order against the suspect, who will appear as one of their own forces and therefore is not automatically designated as a threat.
 * Sabotage: Armed with a pugio, these infiltrators can deliver a swift strike to kill light infantry, and skilled to the point that the opposing commander won't have their announcer notifying
 * Say hello to my little friend: If spotted Frumentarii can fire off their sawed-off shotgun, which has enough firepower to blow anything short of a superheavy infantry off their feet, and are taught not to use it unless spotted. However, limited of ammunitions means that they can only fire it between intervals, and its thunderous report will notify the enemy
 * And your little dog too: If discovered, Frumentarii are extremely vulnerable, especially when reloading their shotgun. Being only armed with a shotgun that needs time to reload and not effective against heavy infantry. In addition, every armies have specially-trained units that can detect them even when disguised, and most of those they easily rip them apart