I agree with pretty much everything that has been said here. An i really want a iron long reach weapon.
I recently looted from ruins an aged voulge and what seems to be an aged hallberd I think ? I think that should be the solution here.
An Iron version of the spear which has better durability, the reach of the lance, but not throwable so it's not overpowered.
It would do less damage than other iron short reach weapons.
The throwable version would be reserved for stone, copper or bronze.
It even makes sense for the reality. You would throw a pilum, but not an hallberd or a voulge.