As Issachar so eloquently put it - stats are invisible and without extensive theory crafting and personal testing it takes a long time for the exact numbers to be produced. However people have do some testing and are happy to rely on the Knowledge that Vitality and Strength Modify Melee Damage for MRD/WAR. As far as the actually numbers showing up within your attributes page; some of it is just down to the Broken Nature of the game in it's current form.