I like the idea of weapons and armor made from multiple materials. It doesn't make much sense to have a solid metal pike, spear, or pick, for example, and shields should probably be made from a combination of metal, wood, and leather. Obsidian swords are currently made from wood and obsidian in the game. A similar procedure would be nice for other weapons.
There's also the problem of having weapons made out of strange materials. Copper vows, for example. Bows should be made out of wood or horn. Crossbows prods should be made out of wood, horn, or metal, with stocks of metal or wood.
The material the bow or prod is made out of should effect how powerful shots fired from the bow or crossbow are. A steel-limbed crossbow should have no problem outshooting a wooden one, but at the moment, it makes no difference unless the dwarf is in melee. the material of the bowstring is made from might also effect the strength of the bow. The strength of the archer would probably effect the rate of fire for the bow as well. steel crossbows/longbows would be more powerful but harder to fire. Low strength might even exclude weaker dwarves from using higher-draw bows entirely.
These are all possibilities for making the bowyer's job more important. If it is a complex, multistep procedure to assemble bows and crossbows (two items needed to make a bow, three for a crossbow), it makes them more valuable items and offsets their
advantages over melee weapons.
Personally, I think that all weapons and armor should be multistep. As the process stands right now, it is no more complex a procedure to make a sword then it is a bowl.
Something like a 'make longsword blades' job at the forge and a 'attach wooden/wire/leather/bone grip' at a the various shops would definitely increase the customization options and make each item feel more unique then just another +battleaxe+