The Rough Riders
Stablemen, commonly known as Rough Riders, in the yard, ride the lay down horses. Historically the tactic of laying down ones horse emerged when scouts could move fast into enemy territory and then "disappear" in the long grass when they laid their horses down.
They would also use their horses as a firing post, in an emergency, as they would offer some cover from fire. There old skills are an integral part of the routine today.
