Currently, the system of Stats has it so that the Stat number you has, whether it be 5, 10, 15, 0r 20, gives you a percent bonus or penalty to your current 'other attributes'.
For example, Defense 20 gives you 200% armor, Defense 10 gives you nothing, Strength 5 makes your attack 50% as powerful as it should be, etc.
I think that a system of Flat Bonuses might be more effective in this regard making characters slightly more sensible.
As it is I think a /Sovereign/ with high strength should be effective no matter what weapon they have, the same thing with defense and armor. If my Sovereign is a giant mountain of a man who's clad in furs and knocks people aside with a giant mace, I think Defense should be able to provide for that.
Further more, the later the game goes, and the higher the technology, the higher the bonuses from equipment will become for the current system, and the worse the penalties will be.
If you have a sword that Provides 18 Attack, and Armor that offers 14 Armor: Someone with Str 5 will have 9 Attack with that sword. Someone with Strength 20 will have 36 attack with that sword. Someone with 5 Defense will have 7 Armor with that suit of armor, and someone with 20 Defense will have 28 Armor.
It seems a little bit excessive, and furthermore; flat bonuses will also provide for sovereigns with weaker equipment, and allow them to still be competitive, though not as good as sovereigns with better equipment.