I'm using "economic actor" to mean an intentional user of scarce means to achieve desired ends. It seems to me that only economic actors could have a dispute.

Babies and young children are a really tricky case for most philosophical systems. Are they full persons, parental property, something else? I'll leave them for another discussion.

People in comas are still treated as property owners. The point isn't that they are incapable of arguing, but rather that we can reason about property titles and whether the person in the coma has the better claim to disputed property. If they have no one to argue on their behalf, then there's essentially no dispute: there would just be someone else using their stuff uncontested. Upon waking from the coma, the person could reassert their property claims.

Am I understanding correctly that the super advanced aliens want to help us? Maybe mass medication or something like that? I guess I'd want to know if they have a better philosophical basis for doing so than our Argumentation Ethics. Presumably, they do have more advanced philosophy, so maybe I'd be convinced by whatever their reasons are. Since I'm not privy to that hypothetical philosophy, I would say they need to limit their interventions to people who opt in.

I'll add that not only can we not understand their communication, they may not understand ours. This would be very similar to our situation with the animals of our planet.