Generally if you see mod tools for existing games (e.g. Skyrim) you'll see that the engine does have inherent support for the base classes (Weapon, Armor, etc) but it relies on data for the specific items, so what i describe above can be the engine (gameplay code) side of that.
Objects, particularly highly sophisticated objects, generally have minimal requirements that determine who can use them successfully. Requirements can be anything from strength to knowledge. At the same time people have skills (or don't have skills) and attributes which lets them use objects. Some people are more skilled than others.
Modelling this requires both the ability to ask an object "What are the minimal requirements needed for somebody to use you?" and the ability to ask a player "How skilled are you really at using this object?"
As a smell test, it doesn't make much sense to ask a sword "can I use you?" How would the sword know? But you can ask the sword, say, "how heavy are you?" It does make some sense to ask a person "can you use this sword?"
And yes, it's not clear at all that every object type corresponds to a first-class language type. You might have a Sword type... but in reality, unless the game is very sophisticated, all bladed weapons do pretty much the same thing. This is where it's useful to take a step back and focus not so much on nouns but also on verbs in our domain language. Swords, axes, ninja stars -- they are all cutting damage. Spears, knifes, polearms -- they are all stabbing damage.
Does it really? I mean, if we're talking about an actual person then sure, since a person can think about the problem and come up with a creative answer. But the object representing a person in a game? That would imply that the "person" object must know all about swords and the requirements for using each of them. How is that better than requiring the "sword" object to know about people and their capabilities?
Swords have attributes (e.g. weight). People have attributes (e.g. strength). Whether a particular person can wield a particular sword is not a question either a sword or a person can answer without introducing unnatural dependencies. It is a property of the environment in which the player and sword both exist, and IMHO is best modelled as some form of external "rule" object, or via a multiple-dispatch method (if your language supports that paradigm).
I also think trying to squeegee it into the language's type system is the wrong approach (for this specific problem, I mean - I'm not saying there aren't cases where doing it in the language is useful) purely because we're going to want the art team to add more monster types and player types, and to be able to change the rules for attacks and damage and soforth quickly on the fly to try out new game mechanics. We're going to want it all in data very soon, so it'd be better to just jump straight to a data-driven design.