400+ Ai on one level?

Hello,

I’am making a rts-tower defense hybrid game, like They are Billions and need to support 400-700 number of ai in one level.I created behavior tree and can run smoothly with 200 ai.I did some research online and i found that people were talking about some kind of Ai Manager to handle the decisions and sent this to other Ai to follow the command.Since the game is tower defense i don’t need any complex logic.Just go A to B point and attack anything on the path in order.But thing is i’am 3d Artist and prefer blueprints.And nobody talking about how to create this Ai Manager and establish correct communication with children while keeping performance maximum.Down below you can see the solutions i tried.But i’am not sure if any of these are proper way to do this.

-Created Character Blueprint as Commander and created another character blueprint as lower ranked soldier.Commander(using Ai perception to find targets) has it’s own Ai controller and uses behavior tree.However lower ranked soldier has also its own controller and behavior tree.Soldier behavior tree is using same blackboard with commander, so this way i can update the commander’s location as blackboard key and get this data to soldiers behavior tree and move the soldier to commander’s location.But this method still not letting me use more than 200 ai without frame drop.So i need a confirmation if this is the proper way to create Manager Ai.

-Tried every ai with their own behavior tree and this kills the performance.So we don’t even need to talk about it.

Questions

  1. Is Ai move to node have any significant impact on performance?
  2. Ai perception vs using traces to find targets?Which one is heavier on performance?
  3. Using communications between blueprints or using behavior tree?Which one is better way to do it when it’s comes to horde and swarm logic.

So as you can see i’am little bit confused about what to do at this point.And i will be grateful if you anyone can help me with this.Any documentation, tutorials or keywords will do.
Thanks.