mellored
Legend
I agree, adding would work well.A better system would be a three-save system which took into account both relevant stats - if your Fortitude save was equal to the sum of your Strength modifier and your Con modifier, and so on. That way, you could stand a decent chance of resisting charm whether you were wise or forceful, but the rare character who was both would be even better.
Reflex = Dex + Int
Will = Wis + Cha
Fort = Str + Con
DC = 10 + stat.