Of course, Neville does embody many characteristics that are worth emulating all on his own, but the more important part of that equation is how his strengths fill a gap in group dynamics that the Marauders were missing. Harry and company need Neville in the exact way that James and Lily and the Order of the Phoenix needed Peter. The difference is that Neville is more than up to the task.
It’s a lesson in self-worth under stronger personalities that most human beings could do with at some point or another. Because society at large insists that the only people of value are leaders and their closest confederates, people like Neville are dismissed at first blush much in the same manner that he is dismissed by his classmates in his first years at Hogwarts. But that lack of confidence from his peers doesn’t lead him to throw in the towel; his self-deprecation eventually turns into a dogged insistence on growing his skill set, on offering his help whether or not it’s been called for, on figuring out how he can best be of use in the coming fight.