If say all those people advanced steadily, the BLM would have no choice but to fire or risk losing control of the weapons. This is what happens when you militarize the police. You might say they are all dressed up and with no where to go.
They are more suited to hunting people down individually in raids in the dark of night. Your dead or disappeared -no cameras and at most an “internal investigation” that will take weeks with the results published on page E-12.
5,000 people against the BLM at the scene is so unfair!/s