Various other classes collect resources to make items for purchase as well. You only have to manage your gold resources, your Heroes will go looking for the other items that they need on their own. A Reward Flag is an offer of gold to perform a s certain task. Attack, Destroy, Steal, Defend, etc. The Heroes all have their own personalities and statistics depending on class.
Warriors are brave and foolhardy.
Rogues are sly, shrewd and greedy. These characters will also give feedback based on their status to you. You will then be able to complete harder tasks with these Heroes. Yes, there will be Henchmen. Tax Collectors get your share of gold that your Heroes bring back.