have you considered that perhaps both player and character skill could enhance eachother?
lets say that once you level up a weapon skill enough, you can learn special skills to use in battle and in the overworld. so combat options become more expanded.
say if i were to level up one of my gun skills, i'd become proficient enough to shoot from a range at the overworld. or if i was to level up my sword skill i could make a disarming attack to reduce enemy attack. or level up my shield skill and learn to stun enemies with a shield bash.
basically the more character skill you have, the more options you have and the more player skill can have an effect.