[Snake]

But then what use would Evasion have, if this gets implemented? And Swaying from Boxer? This, assuming 'Glancing Blow' will reduce over 30% damage.

It just 'not stacking' seems a bit boring. Maybe those passive Evasive skills further increase (additionally) the chances of it activating by their respective reductions (+0.3x/0.15x/0x depending on Armor type)?