I really don't see the `anyone can attack a claimed mob` mechanic continuing shortly after linkshells demonstrate how easy it is to rain on peoples parade via intentionally triggering certain attacks by pulling hate under certain conditions.
Imagine if this were how it worked in XI. Rival linkshells would send their DRK's into Tia fights to zerg from behind and force tail flails to wipe everyone out.

I don't have much faith that SE will continue with that system for long.
Bring on open world.