It definitely is right now, as only one player can play per instance of OpenClonk. Even on a multi-user computer, we end up with multiple user profiles. The question is what this will look like once split-screen play returns.

I think the current solution is more complicated than it needs to be. Players should be more of an ad-hoc thing, decided by the available input hardware. Currently, it's the other way around: You associate a player with a certain input method, and then have to decide on the correct player for the input method you want to use. I think the model I'm thinking of is close to what the Switch does, but I've only played on that once.