Hey, thanks for the affirmation that I made the right call!
For your question, my goal is to have predefined parties initially, very akin to Slay the Spire’s classes. You can see that here:

However, I’m strongly leaning on the idea of eventually giving an unlock to build your own party, which would be tied to its own leaderboard. In that sense, the pre-defined parties would be more like an extended tutorial before giving you the keys to the car.