I would love to support a project that tries to put together observations.
Just revealing things is not so easy, because I would have to go deep into details. However, one thing that I have repeatedly denied is that there is any kind of special mechanics for individual weapons. There is no "this weapon is good against that armour" code. All battle code is abstract. That means that, for example, while right now the javelin is the only one-shot weapon in the game, there is no special "javelin" code, there is only a "ranged weapon with limited number of shots" code. I could turn all ranged weapons into limited shot ones (say, 100 arrows) easily. Same for melee weapons, armour, etc. They have values, but no "if this weapon, then" code.
So everything you observe can be explained in terms of abstract values, such as defense, offense, damage, etc.
Some items have more than one value and increase both offense and defense, for example.