In over 20 years of major city law enforcement and over 35 years of studying violent encounters, I have yet to see or read of a case where someone attempted to disarm a civilian CHL holder whose gun was in the holster and concealed. Attempted disarms of police officers, particularly those with openly carried weapons or drawn ones, happen all the time, but those usually occur in arrest situations that CHL holders aren't involved in. When a bad guy puts his hands on a police officer's gun and attempts to gain control of it, that is a life threatening situation and it is managed accordingly.
I find discussing the legal and tactical aspects of real life incidents to be very worthwhile. However, I find little value in hashing over made up hypothetical situations because, like the one in the original post, they are based on unrealistic incident dynamics.
While I understand and encourage thinking potential situations through before they actually happen and don't disparage anyone for their efforts in this regard, in my experience discussions on how to resolve imagined issues tend to lead to posited solutions that work best in the imagination but don't translate nearly as well into the real world.
I think discussing real world incidents,with all their complexity, to sort out what was done well and what could have been done better is a much more productive exercise.
Just my 2 cents.