Totally confused though to be fair I didn't really get it before either. But it is definitely better to get more use out of variety and not have hundreds of useless characters so I like the intent of the changes. Would be nice to see a few things though...
- Sorting girls as mentioned above. By trait or rarity or active bonuses or remaining affection needed...
- More than +5 affection on a win. At least scale it with rarity? Doesn't feel like anything is being accomplished when you need tens of thousands. Assuming this small amount goes back to the beginning of the game when much, much less would have been needed to make a difference
- Maybe add a new type of character leveling (say for unlocking additional lore or art or something not mechanics based) that can only be gained by a new experience for using them in battles. Also more motivation to cycle through weaker or older girls.