When general manager Dave Caldwell pulls the trigger on the Jaguars’ first-round draft selection Thursday night, he will become the fourth executive to run a Jaguars draft. If Caldwell is to be a success, he is going to have to have a better touch in the draft than the last two men to hold the position — James “Shack’’ Harris and Gene Smith. Their first drafter and first coach, Tom Coughlin, gets a passing grade because he hit on five Pro Bowl players in the first round. But he found just one Pro Bowl player who wasn’t selected in the first round, Tony Brackens, a second-round selection in 1996. Coughlin needed the help of his other personnel moves to make the playoffs four years in a row. He traded for Mark Brunell, found a Pro Bowl castoff in wide receiver Jimmy Smith and signed such free agents as Keenan McCardell, Natrone Means, Leon Searcy, Gary Walker, Kyle Brady and Hardy Nickerson. Those signings, though, got the team into a salary cap hole that led to such unpopular moves as letting Tony Boselli go in the expansion draft. When Coughlin was fired after the 2002 season, former owner Wayne Weaver put the draft into the hands of a personnel executive instead of the coach. But both Harris and Smith were fired for poor drafting. Harris drafted only two Pro Bowlers in eight years, and none of Smith’s players made the Pro Bowl, although some might develop into that status.