This practice is to help the backstop and fielder at 1st post to improve the speed of delivery in trying to get the batter out.
3 players with the ball
1 bowler
1 backstop
1 1st post fielder
The rest of the players line up to to one at the time step into the batting square to dummy hit the ball and try to to beat the ball from the backstop to the 1st post by running as fast as possible to touch 1st post
World Rugby has reportedly conceded Aaron Smith's disallowed try in the World Cup final should have stood.
"It is not only useful for staff who are experienced but a valuable tool for those subject staff who have to take teams."
The variety of sessions across sports - sometimes we steal session ideas from one sport and use them with another.