Potential Sergeants are put through rigorous training and conditioning to test them for emotional and physical weakness. They are also trained in more forms of combat then any other member of the squad.
After training they are often given a blessing of Zeus to make them better leaders.
The role of the sergeant is key to the squad. The sergeant keeps the squad unified both on and off of the battlefield. They keep their spirits strong in war and keep them together at all costs.
They rarely take any other gear rather then the standard issue gear. However the are often given the squad's special weapon or even the squad's heavy weapon.