Wikipedia
In many militaries, a platoon sergeant is the senior enlisted member of a platoon, who advises and supports the platoon's commanding officer in leading the unit.
Usage examples of "platoon sergeant".
But I could create the illusion that everything was being checked, especially if I used the squad leaders and the platoon sergeant as extensions of my will.
And if there was an error in accounting, the platoon sergeant had better know of it first.
I took his squad with me, leaving my platoon sergeant to organize the evacuation of the wounded and the continued security of the perimeter.
Tilles the platoon sergeant and turned his squad over to a young specialist with only three weeks in the country.
Furthermore, the platoon sergeant I had left in the center was armed and likely to be as jittery as anyone else.
A passing glance between the young mother and the platoon sergeant aroused my suspicion that he had violated her in some fashion during my absence.