Sadly, the pure fighters, barbarians, paladins and rangers will wind up destroying the competition if you factor in attack bonus per level as a means of accuracy. While you could level the playing field by making it a flatter dex based check, it would unfairly misrepresent said warrior classes who would suddenly be able to shoot the fleas off a dog's back when they left the bar and went back to adventuring. The poor wizards and sorcerers wouldnt be able to hit the broadside of an orc most of the time unless they used true-strike, which should certainly be against the rules.