And look at a map of downtown Richmond. What is around the area? To the North is a very libtarded VCU main campus. To the Northeast is a major state university hospital. To the East is an Interstate. To the SOuth is a River. To the west is a dense urban zone. A crowd of 30,000 or so milling around is gonna bleed over into and disturb the neighborhood. A crowd that will have to be pretty much respected because every single one will be armed. If Northam tries to stage a goat rodeo in that setting it would get real weird fast. I expect the State Police will make sure everyone gets in and out safely. To provoke a riot in that setting would not work out well for Northam or any of them.
They will invite a bunch of nazis... then take pictures of the 2a supporters standing next to the nazis. Then they will use antifa to agitate them into a conflict.... just like in Charlottesville.
It is all an attempt to paint 2a supporters as violent and dangerous.
But you assume that they want a boring, peaceful protest. It is their intentions to seed the crowd with bad actors who will try to start a riot so that the anti-gun crowd can portray them as insurgents.