These men come from various noble families in order to fight for their kingdom and do so in order to uphold their family traditions and maintain the reputation that their family has created and held for many generations. Their nobility provides them with funds for extensive combat training and top quality armour.
Treat these units like recruits; they need to be upgraded as soon as possible as in their current state even bandits and brigands are a serious threat for them. In battles, move them far away from the actual fighting, they always come mounted so speed is one advantage for them. Don’t neglect these men as they have potential to upgrade into powerful units.