We had weapon speeds, weapons more effective against different types of armor, weapons more effective against larger opponents and so on long ago.
It was a cool idea that we ignored after trying it. I mean, it's great occasionally but what armor do monsters have? Does a heavily armored monster like a bullette count? Weapon speed didn't really change all that much after a round or so and damage vs size was just kind of finicky.
Which of course was just my experience. Easy enough to add some of that stuff back in. There's always going to be a balance between simplification and realistic.
Used sparingly at key points in a meaningful battle it could add some good tension and drama. Perhaps it wouldnt be accounted for in a general toe to toe slug fest but might in a called shot or a death blow when it really counts.