Skyrim's system is great. Extra complication isn't needed.
You could add on as much complication as possible. Why not have 15 categories of skills for short swords alone? You could have a hundred different skills that, in the end, only really increase damage. We don't need multiple metasystems to handle single, generic ideas such as damage increase. New functionality is accounted for in unlockable abilities while generics are their own ability, upgradeable multiple times.
A brilliant idea for metasystems....
Let's create a separate game for each weapon type. Make at least 100 different skills in various categories just for that weapon type. The game consists entirely of managing these skills. All questing and combat is automated. So it's an overcomplicated skill-building sim. yes. Create as many separate skills as possible with as many categories as possible. Also, each individual upgrade must do as little as possible to ensure things stay overcomplicated.