What might have happened if Helton signed with the Padres?
Since he was drafted by the Padres right out of high school, he almost definitely would have spent more time in the minor leagues than he did with the Rockies. The Rockies drafted him in 1995 and by August of 1997, he was in the major leagues.
By 1998, the Rockies gave Helton the reigns to be the full-time first baseman as he played in 152 games. The Rockies let Andres Galarraga walk in free agency after he hit 41 homers, 140 RBI, and hit .318/.389/.585. He also came in 7th in NL MVP voting.
Helton did play some left and right field for the Rockies in 1997 but they had a great outfield of Dante Bichette, Ellis Burks, and Larry Walker, who won the NL MVP Award in 1997. So, entering 1998, for Helton to get playing time, it was clear that he would have to play first base.
For the Padres, that likely would not have been a foregone conclusion. The Padres everyday first baseman at the time was Wally Joyner, a left-handed hitter who had been in the majors since 1986.
His best two seasons were his first two seasons as he was an All-Star in his rookie season, ranked 8th in MVP voting, and came in 2nd in Rookie of the Year voting to Jose Canseco (who oddly enough, ranked 20th in AL MVP voting). In 1987, Joyner came in 13th in AL MVP voting but he never was an All-Star or ranked in MVP voting again.
That doesn’t mean that Joyner would have been dethroned at first base.