Vegas Golden Knights prospects Paul Cotter, Jake Leschyshyn, and Jonas Rondbjerg are proving they belong with the big club. Paul Cotter, Jake Leschyshyn, and Jonas Rondbjerg each got their first call-up to the Vegas Golden Knights last season, and their progress has only continued to trend upward through training camp. All three forwards have been members of the Henderson Silver Knights over the past two seasons. Now it’s looking like those days could very well be nearing an end. Golden Knights coach Bruce Cassidy told the media after the team’s preseason overtime loss to the Los Angeles Kings on Monday…