My force is a little unique.
Since it is all 1st company my Sternguard units have multiple sergeants in them.
They are the Vets Sergeants that accompany other squads throughout the chapter.
So this guy will be the model that would be in charge of them, a Master Sergeant if you will.
I always though the Master of Recruits model looks like he would be much more at home in a unit of Sternguard,he carries their modified bolter.
That is the model I am using represent Sergeant Wagner in smaller games he will be the captain.
In Larger Games when I field the Chapter Master he will be a sergeant.