first thing that comes to my mind is either change tier of wood weapons or add something behind them like enchantings or particular bonuses because honestly theres no way any wood sword could be better than steel, aluminum etc,
maybe there could be a little storyline behind wood used for weapons (the wood from the x forest is much powerful and can make a sword that will never break! or stuff like that)
have you considered the option to mix different elements/metals to improve certain stats of the weapons? for example aluminum is one of the lowest tier in the game, it's a very light material but it's not so strong; but when it's mixed with other materials it can become much stronger
atm i have lots of ideas about the weapons but those might be excessive/stupid or would make the game too complicate