I think every persons system would be made to be just how it needed to be. I have coconsciousness with a few alters and no coconsciousness with an unknown number of others (quite a few). The ones I have coconsciousness with share life responsibilities. The ones I don't (but know of through my T or other means) have ideas memories and or feelings that are beyond my ability to tolerate. The group of ones that are coconscious weren't always this way, we only started being able to be aware of eachother and communicate through therapy and our t helping us develop those skills.