I think what Trig said is valid. In order to craft a set of full plate for instance you need to go to an armourer customize the look, pay the cash, and wait a set amount of days and come back. The limiting factors should be how well off the settlement is (trade caravens coming through/number of succesful raids), so an impoverished city is limited to full mail and anything more advanced is grayed out. Assigning minor crafting tasks for unique charms wouldn’t get in the way if done right, with a focus on battle instead of collecting. So if you assign someone to make an orc ear charm, the objective to completing it would be to have that person kill orcs, every kill has a 20% chance to complete the task, with stronger orcs resulting in better stats on the charm (morale buff vs. morale buff + inflict morale debuff on orcs). They can accomplish these crafting tasks as many times as they like (or until they die) but the charms are locked to the players that made them, stopping one super soldier from being responsible for everyone’s charms. However ones that you find or buy outside this crafting system can be assigned to anyone.
Edit: here’s another idea for a charm, Four Leaf clover, adds a very slight bonus to hit chance, melee, and ranged defense. Every tile moved by the character during a battle has a 5% chance of completing it.