I've done some roaming monster bands with natural equipment, only issue is making the castes for different loadouts CASTE:MALE_RSWORD_IRON,
CASTE:MALE_LSWORD_BRONZE,
CASTE:FEMALE_RMACE_IRON_LMACE_BRONZE(dual wielding), etc etc
and then setting up all the attacks to mimic the weapon attacks, however there is a vastly different math calculation to a Item and a bodypart attack of size weight and contact area. So some values have to be tweaked to prevent say what the attack values for a sword slash is not 10x more powerful when directly slapped onto the creature attack
(Where a weapon will always be the same size either if a Giant or a Kobold is holding it, a bodypart scales with the creatures size. so contact area needs to be lowered in bodypart attack, and velocity and such.)
I've done it, it works just a bit more clunky. One I enjoy most is my Undead zombie civ(for ambushes/invastions) with their wildlife clone of feral zombies that roam about.
EDIT:
Another issue is when they get chopped up and you manage to butcher them they will leave "<metal name> chunks" that belong to them, but you can atom smash those parts or have a custom reaction to try to salvage the metal from BODYPART itemtypes. All depends on how much work and detail you want to go into for that. It is possible just a bit finicky for balancing it. And dealing with the outcome, Also natural shields don't work for blocking, and would have to be a rather thick bodypart to 'deflect' blows to it without being severed from heavy blunt attacks or really sharp items (The dwarf slashes the goblin's bronze shield with their Cotton Candy Sword, the servered part flies off in an arc)
Plus if you don't customly define all the natural attacks for different size creatures you have to make due with an easy generic one that you have to accept that a smaller creature will have a smaller contact area and can cut into things better (like a spear) and a larger one like a giant will basically have a sharp club (may or may not cut things but rather bludgeon them to death due to the size of the natural part)