Composite weapon construction could be done in a simpler manner;
Sword: Haft/Blade (core metal) + Grip (optional; leather)
Spear: Haft (wood or metal) + tip (metal or stone)
Axe: Haft (wood or metal) + blade (metal)
Mace: Haft (wood, bone or metal) + Head (Optional, accounts for bone clubs/nightsticks; metal, stone)
Hammer: Haft (wood or metal) + Head (metal or stone)
That would work well, but composite weapons probably ought to wait until partial stacks are in place. Otherwise it makes making weapons very material-heavy. As it is having the handle of an obsidian short sword take up as much wood as an entire door is kinda silly. Although I suppose buckets and such have the same problem.
I look forward to a time when stacking is in, where when you smelt a lump of iron ore, you get a stack of bars that could be used in various numbers.
say you might smelt a lump of iron ore and get 23 bars of iron out of it (maybe miners skill determines how big a lump of ore you get, and smelters skill further determines bar output, with a bit of randomness thrown in)
now maybe you would need 20 bars to make an iron door, or 10 to make a breastplate, but only one bar needed for the tip of a spear etc.
this would be a bit more historically accurate really too, with low skilled miners/smelters, metal might be a little more sparse, so using it sparingly on weapons like spears, instead of pumping 5 bars worth or so into a sword would be much more economical
I also look forward to days where weapons are composites of their parts. stoneworkers fashioning speartips or axeheads out of flint (in the absence of metalworking) swords with gold inlays in the hilt etc. maybe materials used could have a bearing on the final product, ie a mace with a wooden haft might be more prone to breakage than one with a metal haft.
edit: also this shouldnt just extend to metal bars, im all for felled trees offering larger quantities of wood, perhaps in various forms, trunks could be fashioned into planks or blocks or similar larger items, while limbs might be fashioned into poles, hafts, handles and that sort of thing. both should also be capable of being split into 'snack size' logs for fuel burning or ash/charcoal creation.
infact you could probably go the whole hog if you wanted to, and even have a yeild of twigs that could be used for fashioning bolt or arrow shafts. this would all have to come back to stacking support though.
another edit: and i almost forgot, what about bark too, im sure there are a million uses for wood or tree based products. weaving baskets or fences, making cordage i could probably go on all day.