I think it is pretty ok as it is now, I mean the effects of the items. After all, the game is mostly trying for realism.

However, I think that overall having transferrable special items makes the game a lot more versatile for modding. Arthurian mod can have Excalibur, giving a lot of boost to a generals hp valor etc.

Also, some fantasy mods might have enchanted items that are not necessary even unique.