Yes, sure they shouldn't get as far as the aircraft if the ground staff do as they should.
Contract check in/ground staff in ports like DPS are more likely than not, going to avoid the confrontation involved and not just for cultural reasons.
If and when they do get to the aircraft those at the door ought to be the ones identifying those passengers who are [visibly] intoxicated and advise the Captain.
If the report is correct these morons were intoxicated and started misbehaving 1/2 hour out of DWN.