The Vietnamese had room to maneuver and hide and had the support of the locals. In addition you overestimate how little the Chinese government gives a shit about the average citizen. In such an engagement there will be no "hearts and minds" war. If they decide to go the military route they will flood HK and massacre anybody who gives off the slightest whiff of sedition.
Personally I think they'll just continue arresting and making people disappear to the mainland so there is nothing damaging on the news.
Personally I think they'll just continue arresting and making people disappear to the mainland so there is nothing damaging on the news.