Two points regarding a rematch:

Today I learned, that when someone creates a rematch based on a history game and invites with that rematch some of the players and deletes them, when he sees no fast reaction, that player can't rejoin the game, when he gets notice of it.

Furthermore: Why a game with an original random team selection is created as a preselect team game?

Nowadays when creating a preselected team game from scratch, you get a warning, that those games don't fill soon. Why there is with a rematch not at least an option, to choose team config?

Hmm, I won't comment on what is the best UI approch. But there is one way to get what you want. Instead of using rematch, go to Full Settings, find the template name and click on it. (Template : [template name] ) This will prompt a create new game box, which let's you change all the game settings.

Rematch is designed to be a one-click play feature.