I haven't seen this specific proposal made as a buff for Careful Attack, but I quite like it for both Flavor and Balance.
Careful Attack:
To Hit: Str/Dex + 3 [in PHB it is Str/Dex +2]
Damage: [W] + WIS Modifier [in PHB it is just Weapon]
From a flavor standpoint I like adding the Wisdom in...
