You will unlock additional classes that characters will have S rankings in. I just got the first one, and I assume the class system won’t really come into its own until you’ve gotten a bunch more.
I’ve been trying to switch around which character/class I’m playing, but I’ve only found a couple that click with me so far. Obviously Swordfighter does as you’re introduced to it slowly and don’t have a choice really but to get comfortable with it. I’ve also found Medic Gunner to be enjoyable. Although, I wish the AI characters were smarter with area buffs I’ve dropped. Hey dumbass tanks who are almost dead, step two feet to your left into the regen ring. I struggle with the tank classes same as I do in an MMO. Holding aggro requires some sort of attention juggling skill that I do not possess.
I will say, I think I’d have preferred the class swapping setup more with a more traditionally sized party of 4. Trying to track what character is doing what role and what that’ll look like in the crowd is really tough with the bigger party size. I know they’ve done some work on the UI to help make the info you want clear, but it’s still tough with other things. Back to the Medic Gunner, since my attackers won’t move to the power ring on their own I have to find where they are camped and drop it near them. But that means I have to pick out which characters are the attackers, which takes some work.
All my complaining aside, I’m really enjoying this game. XC has always just worked for me in spite of the flaws that they insist on carrying over from game to game.