My model requires immutable identities: without them, there is no temporally consistent individual meaning. As I know that time is always passing, temporal consistency is required. Although my body may disappear without a trace of its contents, my identity is recorded in history/spacetime.

I also know that people can disagree on politics, from which follows that there can be multiple different non-nested identities. If you want, you may still combine conflicting identities into a "conflicting superidentity" to achieve an algebraic style. At the boundary of conflict, though, communication is unlike that inside the volume of agreeing or orthogonal agents. Cooperation is replaced by either trade or fight.

> less likely explanation

It is less likely for you only because you prefer simpler ones. My evaluation of ideas, for example, is not so straightforward.