That is a conservative estimate.
Calling what was obviously thousands "several hundred" is not a conservative anything. It's either a deliberate liberal lie or a lazy/cowardly parroting of a deliberate liberal lie.
Watch the video on post-13 and keep track just how long marchers, 8-10 abreast, keep marching by. Then note that when the camera turns away the end of the march is still not in sight.