With six bonus point wins from six matches, Randwick have been close to perfect so far in 2019.  But the Galloping Greens, who won both the first and second grade colts premierships last year, face their toughest test of the season on Saturday against Manly and play three top four sides in their next four matches.  Randwick have a bye after the Marlins clash, then face Sydney Uni and Gordon in consecutive weeks in June. “I think we’re building nicely but we’re coming into of a string of tough games,” Randwick colts coach Peter Dumbleton told Rugby News.  “We had a good hit out last week against Rats and that was a very good challenge. Although the scoreline probably flattered us a little, I did think we deserved to win.” Randwick, Manly and Sydney Uni are all undefeated so far in 2019 and while neither side has played one another yet this season, Dumbleton said he’s been impressed with the Marlins so far.  “They’re going to be very tough to beat.