Hmm, while I haven't caught up with V13 yet (I just started a new playthrough) and thus don't know who's in the main group currently, let's look at the six characters who to me, are the main characters (Player, Aelita, Melia, Ren, Venam and Erin) and put them through the classic Five Man Band + Sixth Ranger format, shall we (Plus a few other characters and archetypes)? (Note that some of these characters could easily fit multiple of these tropes, but I'll try my best to justify why I place them there)
Player: The Hero - The main character of their story. The Hero is often the person who the plot focuses on. The hero can be a male or female depending on the writer. The Hero's personality can range from being an all-loving hero or an Anti-Hero depending on the plot (Do I really need to explain this one? Just swap out "depending on the plot" with "Depending on the player's choices")
Player/Aelita/Melia: The Leader - The one who leads is usually the Hero but not always. The Leader who is not a hero will often be the Big Good of the story itself. The leader will often be considered more reasonable for the actions of their subordinates and will decide what action will be most beneficial for the world or for the organization they lead as a whole (You already pointed out that Player and Aelita fit this role. Melia because she's the closest thing the cast has to a "Big Good".)
Aelita/Erin/Ren/Venam: The Lancer - The Second in Command after the Hero. The Lancer in the group after the Hero will be the most responsible and the one to take command once the Hero is not available. The Lancer at times depending on the story can be strongest member of the group after the Hero. Sometimes The Lancer can be or was the Rival to the Hero, who decided to join the group for various reasons.
(Aelita again for obvious reasons. Erin is arguably the most responsible member of the team after Player and Aelita. Ren used to fill the role, being arguably Player's main Rival in the game, but lost that role after he joined Team Xen. Venam could be said to be The Lancer to Melia if you count Melia as one of The Leaders. I'd take this one with a grain of salt though, because Venam isn't exactly the most responsible character out there)
Erin - The Brains of the group. The Smart guy will act as the most intellectual member of their group. He or She in this category will often be the most resourceful when their comrades are in the most desperate situation and will act on how to get out of a specific situation. The Smart Guy would be the person to pick up on something that was amiss in any event that occurs. (Erin is pretty much the smartest in the characters i mentioned)
Player- The Big Guy - The Brawns of the group. The Big Guy is considered to be the physically strongest member and the largest of their team. The Big Guy has been known to be unflinchingly loyal to his or her teammates in any situation, they can be counted on. The Big Guy can also be the most combat effective in battle and at times be a one-man army. (Player is the only one I couldd fit in this role, being the strongest in the group. He's probably not the largest, but this is frickin Pokemon. A character's physical size in these games isn't an indicator of strength.)
Melia - The Chick - The Peacekeeper of the Group who often represents the moral compass to the group during their adventures. Depending on the writers, the Chick can also be the main love interest to the Hero. The Chick in the story is usually female but not always. (Again, Melia's basically the closest thing the group has to this trope)
Erin/Ren - The Sixth Ranger - The Latest Member of the group. Usually this member of the group would be the last member to join the group and is always a new member who appears late into the story. The Sixth Ranger can sometimes be a previous and recurring enemy that has fought with the heroes but has decided to join the heroes. The Sixth Ranger for example can sometimes be considered the atoner for the group as they were enemies or pawns to an even greater evil and decides to redeem themselves for what he/she did (Erin joins the latest in the group, alongside Ren rejoining the group in Chapter 13. Ren also fits the "previous enemy" bit.)
Alice/Allen/Kanon - The Tag-Along Kid - The youngest member of the group and/or sometimes the most inexperienced. This member can be a the Hero's Sibling or someone else's sibling. Often times, the tag-along kid would be the most immature one of the group which leads to comical moments. (Alice and Allen are self explanatory, Kanon is easily the least experienced in the crew)
Braixen/Delpha - The Team Pet - The Animal member of the group. This group member serves as companion to the group and at times be amongst the closest of the group especially to the Hero early on the story. In many moments, this member comes through for the team on tight situations such when a its owner is struggling or use it's natural abilities to help the heroes with important matters like solving a mystery or finding something amiss. (While she doesn't really fit the "close to the hero" bit, I'd say she fits the rest of this trope pretty well.)
Again, I dunno their characterization in V13, so feel free to point out if I'm wrong about any of these.