I have yet to see a game where this is even remotely an issue. The 20 items are just important items to track. Also it isn’t really for encumbrance as much as it is to point out the need to only track that which is important instead of every little thing.
The argument that an unarmed strike does as much damage as any other weapon is… not the best to use, as that can be said about ANY weapon vs ANY weapon.
When you are rolling your Action Roll to attack, this is a roll of how well you use the weapon/item, and is not representative of the weapon/item itself.
I posted an alternative awhile back to address some of the concern that @VanGo mentioned above, as well as the concern about disarming someone (though disarming isn’t about making them “unable” to attack, but rather to remove a particularily deadly weapon or item from a person’s hand, or ranged attackers) and they can just attack “anyways”.
I haven’t looked at it in awhile, and it might need work, but the basic premise in the first post I think still stands well. Basically further expounding on the “lack of training” idea: