By Sam Frost Sky Sports pundit Andrew Coltart has hit back at Wyndham Clark’s suggestion that the PGA Tour should reduce the size of its fields and put the bottom 20 players each season at risk of relegation. The US Open champion, one of the tour’s new-found stars, told reporters at the Arnold Palmer Invitational at the weekend that he agreed with Rory McIlroy’s wish for the tour to be more “cutthroat”, making it harder for players to retain their membership. Clark, who finished second at Bay Hill behind world number one Scottie Scheffler, suggested the tour should reduce its membership to 100…