What is it you mean by "communication"?
Like for example, an entity attacks another one. The attacker entity would send an "Attack" message to the attacked entity.
Right, although perhaps something that could include more complex communication, like the entity representing the flagship of a fleet sending tasks to only the entities within the fleet, or user input changing the state of a group of entities.
It would be pretty cool if the communication could be a two-directional conversation as well.
Obviously a lot of this stuff is case-specific. I'm just wondering what general setup you all think would me most conducive to implementing these sorts of behaviors.