Post Marian Romani Units.

[Magister Militum Titus Pullo]

I usually prefer mounted units to act in command of army in the absence of a general. Sometimes, I would have several full armies campaigning together in far off enemy territory, with a single general between them. I would rotate the officer between them if one of those expeditionary forces should suffer exceptional casualties in battle.

[antisocialmunky]

Heh, I usually stick each man with his stack. The captain goes down with the ship.

[Magister Militum Titus Pullo]

If during one of my agressive incursions, one of the stacked forces without the chief present should stray ahead of it's buddies, and is engaged in combat with the enemy, but it performs well enough in battle to earn it's de facto commander a "Man of the Hour" award, then all the better. A captured city has a governor, and the main force still retains a field commander of due rank and probable competence.