iron is pretty easy to get a lot of, just find a swamp with tons of crypts, place all the loot in a boat and you can make a full set easily, plus you need 10 withered bones for bonemass anyway so you might as well do both

also for bonemass if you think you’d be able to skip iron but are also afraid of death fighting him up close wearing iron armor there’s clearly something wrong, just grab a mace and shield with a poison potion and beat the ♥♥♥♥ out of him, if you’re roaming the swamps with troll armor there’s 0 reason you should need to head to the mountains for frost arrows to kill him