There's no need to shoot cops on site straight out the gates like that. If you march together, then the smart move on their behalf would be to observe, record, and then try to ID you for a later arrest. Simply staying together and protecting your identity may be all you need in such a scenario. They may even give in somewhat if you're a big enough and dedicated group, but again, their endgame is to scoop everyone up afterwards if they can play that route. Think Bundy Ranch Standoff.