Kingarthur.
Usually different sects in Islam have there different compounds but in general they all follow the same ritual. Few years ago, people from a certain country tried to use the Hajj for political goals, this was met with a strong response and it was made very clear that such moves are not acceptable, people are there for one reason and one reason only.
Imagine over 2 million moving at the same time from one place to another, that's a logistical nightmare, accident do happen, usually from people being trampled by other people, or a fire in a compound, every year brings more improvement in security by opening new roads and tunnels, new fire prevention measures etc...
Never heard of hundred of peoples dying from errant stones, usually the stones are as small as pebbles, injuries are common yes but that was before the opening of the improved site.
It is very astonishing that while all this people from all over the world, are there in the same area for about a week the recorded incident of fights or crimes is very much less than the end of a single football/soccer match. People are there for those few days to accomplish one thing, and a lot of them went through a lot of sacrifice to get there.
One event i will never forget, a son carrying his old mother and walking few miles to get to Arafah, the smile never left his face.