Hi, Raddonut :D
Sure!
there's an option in the campsite (fireplace) to rest and disband all the characters so they are available in the campsite to make the team with your favourite characters.
To run such option you need to use the fireplace menu, or the clock/fireplace menu in the player house in the capital city after purchase it.
I hope it solves your question selecting characters ^^
Let me know about any additional information you need :D