I probably should have said wrestling. From what I've seen, the Shivworks/Craig Douglas types, and many other instructors are taking wrestling controls and movements like arm drags, the 2 on 1 Russian tie, the duck under, and various hand/grip fighting principles common in wrestling and applying them to the weapons environment.Unfamiliar with Shivworks to answer but cannot see how grappling would not be involved in any retention/disdisarm
Not to say that most grappling styles don't have similar movements. We only move so many ways. It just looks to be based heavily in wrestling.
Id be interested to see the Kung fu practitioner's approach to the problem.