“Why didn’t the men in that crowd, being attacked, stand up against them? “
They acted as individuals would, faced with a superior force. If 40 men felt they were pert of a team they’d yell Let’s Roll and move in.
Remember this took only a few minutes- the yute were organized. 120 seconds is not a lot of time to recruit a defensive team.
Also, the men were on defense- probably most had kids and wives to look after, and not go charging alone into a mob of hundreds of hostiles.
The people who organized this probably had the crowd dynamics worked out. They wanted their troops to have a quick and easy success, so that next time, they could be pushed a little further.
That's it. Anyone who thinks this was just spontaneous mayhem has blinders on.