I think Giorno is the closest Jojo to Jonathan, in that he has an absolute conviction that good will prevail over evil. It's sketchy of him to assume that his dream is on the side of good 100% of the time, but with the kind of terrible people he's faced against (he really took out the worst garbage: Polpo, Melone, Ciocolatta, Diavolo), he is certainly the lesser of two evils, and thus it is the rule of his world that he should prevail, even if from the outside his odds of success seem low. He's not a chancer: good will prevail, that's the end of it.
Most Jojo take for granted they will win the fight, but Jonathan and Giorno are the only 2 that (I think) believe in a higher purpose, or see themselves in an archetypal battle between good and evil. Joseph is on a personal journey and trusts his wits, Jôtarô trusts his own strength, and Jôsuke is just a kid on an adventure where he happens to win most of his fights.